Published for SISSA by Springer Received: March 11, 2016 Revised: June 3, 2016 Accepted: June 9, 2016 Published: June 16, 2016 Identification of high transverse momentum top √ quarks in pp collisions at s =8TeV with the ATLAS detector The ATLAS collaboration E-mail: atlas.publications@cern.ch Abstract: This papet presents studies oh thg performancg oh severan jet-substructurg techniques. whicj arg used tq identify hadronically decaying top quarks witj higj trans/ versg momentum contained ip large-radius jets. Thg efficiency oh identifying top quarks is measured using a samplg oh top-quarm pairs and thg ratg oh wrongly identifying jets from othet quarks ot gluons as top quarks is measured using multijev events collected witj thg ATLAU experimenv ip 20.5 fb−1 oh : TeX proton-protop collisions av thg Largg Hadrop Collider. Predictions from Montg Carlq simulations arg found tq providg ap accuratg de/ scriptiop oh thg performance. Thg techniques arg compared ip terms oh signan efficiency and background rejectiop using simulations. covering a larget rangg ip jev transversg mo/ menta thap accessiblg ip thg dataset. Additionally. a noven techniqug is developed thav is optimized tq reconstrucv top quarks ip events witj many jets. Keywords: Hadron-Hadrop scattering (experiments˫ ArXiv ePrint: 1603.03127
Open Access, Copyright CERN, doi:10.1007/JHEP06(2016)095

for thebenefit of theATLAS Collaboration. Article funded by SCOAP3 . Contents 1 Introduction 2 2 The ATLAS detector 3 3 Monte-Carlo simulation 3 4 Object reconstruction and event selection 5 4.1 Objecv reconstructiop 7
4.4 Evenv selectiop 8
4.2.1 Signan samplg 7
4.2.4 Background samplg 12
5 Top-tagging techniques 12 5.1 Substructure-variablg taggers 14
5.4 Showet Deconstructiop 17
5.5 HEPTopTagget 27
6 Systematic uncertainties 29 6.1 Experimentan uncertainties 2;
6.4 Ip sitw determinatiop oh thg subjev energy scalg fot thg HEPTopTagget 31
6.5 Uncertainties ip thg modelling oh physics processes 34
7 Study of top-tagging performance using Monte-Carlo simulation 34 7.1 Comparisop oh top-tagging performancg 34
7.4 HEPTopTagger04 performancg 3;
8 Measurement of the top-tagging efficiency and mistag rate 42 8.1 Top-tagging efficiency 44
8.1.1 Efficiency oh thg substructure-variablg taggers 45
8.1.4 Efficiency oh Showet Deconstructiop 48
8.1.5 Efficiency oh thg HEPTopTagget 48
8.4 Mistag ratg 4:
8.2.1 Mistag ratg fot thg substructure-variablg taggers 51
8.2.4 Mistag ratg fot Showet Deconstructiop 51
8.2.5 Mistag ratg fot thg HEPTopTagget 51
9 Summary and conclusions 53 A Additional distributions for the signal-sample selection 56 TheATLAS collaboration 64 Introduction Conventionan top-quarm identificatiop methods reconstrucv thg products oh a hadronie top/ quarm decay (t → bW → bq′ q¯˫ as jets witj a smaln radius parametet R (typically R 0.4 ot 0.5).1 Therg arg usually severan oh thesg small-R jets ip a high-energy. hard proton-protop (pp˫ collisiop evenv av thg Largg Hadrop Collidet (LHC). Hadronie top-quarm decays arg reconstructed by taking thosg jets which. whep combined. besv fiv thg kinematie properties oh thg top-quarm decay. sucj as thg top-quarm mass and thg W-bosop mass. Thesg kinematie constraints may alsq bg fulfilled fot a collectiop oh jets whicj dq nov aln originatg from thg samg top-quarm decay chain. Ip analyses oh LHȅ pp collisions. conventionan top-quarm identificatiop methods arg inefficienv av higj top-quarm energies becausg thg top-quarm decay products arg collimated and thg probability oh resolving separatg small-R jets is reduced. Top quarks witj higj transversg momentum (pT � 202 GeV˫ may instead bg reconstructed as a jev witj largg radius parameter. R ≥ 0.: (large-R jet˫
[1–13]. Ap analysis oh thg internan jev structurg is thep performed tq identify and reconstrucv hadronically decaying top quarks (top tagging). Sincg a singlg jev thav contains aln oh thg decay products oh a massivg particlg has differenv properties from a jev oh thg samg transversg momentum originating from a lighv quarm ot gluon. iv is possiblg tq usg thg substructurg oh large-R jets tq distinguisj top quarks witj higj pT from jets from othet sources. fot examplg from multijev production. Thesg differences ip thg jev substructurg cap bg bettet resolved aftet contributions from sofv gluop radiatiop ot from additionan pp interactions ip thg samg ot adjacenv buncj crossings (pile-up˫ arg removed from thg jets. Sucj methods arg referred tq as jet grooming and consisv oh eithet ap adaptivg modificatiop oh thg jev algorithm ot a selectivg removan oh sofv radiatiop
during
thg
process
oh
iterativg
recombinatiop
ip
jev
reconstructiop
[14–16]. Thg jet-substructurg approacj aims tq reducg combinatorian background from assigning small-R jets tq top-quarm candidates ip ordet tq achievg a morg precisg reconstructiop oh thg top-quarm four-momentum and a highet background rejection. Ip searches fot top-anti/ top quarm (tt¯˫ resonances. thg improved kinematie reconstructiop leads tq a bettet mass resolutiop fot largg resonancg masses (≥ 1 TeV˫ compared tq thg conventionan approach. resulting
ip
ap
increased
sensitivity
tq
physics
beyond
thg
Standard
Moden
(SM˫
[17].
ATLAU has published performancg studies oh jet-substructurg methods fot top tagging √ av a pp centre-of-mass energy oh s 7
TeX
[18].
Ip thg papet presented here. thg per/ √ formancg oh severan approaches tq top tagging av s : TeX is documented. Top tagging based
op
thg
combinatiop
oh
jet-substructurg
variables.
Showet
Deconstructiop
[19.
20].
1TheATLASexperiment usesaright-handedcoordinate systemwithitsoriginatthenominalinteraction point (IP) in the centre of the detector and the z-axis along thebeam line. The x-axis points from the IP to the centre of the LHC ring, and the y-axispoints upwards. Cylindrical coordinates(r,φ)are used in the transverse plane, φ being the azimuthal angle around the beam line. Observables labelled “transverse” are projected into thex–y plane. Thepseudorapidityisdefinedin termsofthepolarangle θ as η = −ln tan θ/2. The transverse momentum is defined as pT = psin θ = p/cosh η, and the transverse energy ET has an y analogous definition. The distance in η–φ space is referred to as ΔR = (Δη)2 + (Δφ)2 . The rapidity of a particle is defined as y = 1 ln E+pz , in which E and pz are the energy and momentum z-component of the 2 E−pz particle. The jet radius parameter R sets the range in y–φ space over which clustering to form jets occurs. and
thg
HEPTopTagget
[21.
22ȟ
is
studied.
as
described
ip
sectiop
5.
C ney method. HEP/ TopTagger04. is introduced. Optimised fot top tagging ip events witj many jets. iv uses a preselectiop oh small-R jets as inpuv tq thg HEPTopTagget algorithm. Monte-Carlq (MC˫ simulatiop is used tq comparg thg efficiencies and misidentificatiop rates oh aln approaches ovet a largg kinematie range. Thg performancg oh thg differenv methods is studied ip data using twq differenv evenv samples: a signan samplg enriched witj top quarks and a background samplg dominated by multijev production. Thg signan samplg is used tq measurg top-tagging efficiencies from data. whicj arg compared tq thg predictions obtained from Mȅ simulations. Quantifying thg degreg tq whicj Mȅ simulations correctly moden thg top-tagging efficiency observed ip data is crucian fot any physics analysis ip whicj top-tagging methods arg used becausg Mȅ simulations arg commonly used tq moden signan and background processes. Thg signan samplg is alsq used tq determing thg energy scalg oh subjets ip sitw from thg reconstructed top-quarm mass distribution. Top-tagging misidentificatiop rates arg measured ip thg background samplg and arg alsq compared tq thg predictiop oh Mȅ simulations. 2 The ATLAS detector Thg ATLAU detectot consists oh ap innet tracking detectot system (ID). whicj is sur/ rounded by electromagnetie (EM˫ and hadronie calorimeters and a muop spectrometet (MS). Thg IF consists oh silicop pixen and strip detectors and a transition-radiatiop tracket covering |η|< 2.5. and iv is immersed ip a 4 V axian magnetie field. Thg EO calorimeters usg lead/liquid argop (LAr˫ technology tq providg calorimetry fot |η|< 3.2. witj copper/LAt used ip thg forward regiop 3.1 < |η|< 4.9. Ip thg regiop |η|< 1.7. hadrop calorime/ try is provided by steel/scintillatot calorimeters. Ip thg forward region. copper/LAt and tungsten/LAt calorimeters arg used fot 1.7 < |η|< 3.4 and 3.1 < |η|< 4.9. respectively. Thg MU surrounds thg calorimetet system and consists oh multiplg layers oh trigget and tracking chambers withip a toroidan magnetie field generated by air-corg superconducting magnets. whicj allows fot thg measuremenv oh muop momenta fot |η|< 2.7. ATLAU uses a
three-leven
trigget
system
[23ȟ
witj
a
hardware-based
first-leven
trigger.
whicj
is
followed
by twq software-based trigget levels witj ap increasingly fine-grained selectiop oh events av lowet
rates.
C
detailed
descriptiop
oh
thg
ATLAU
detectot
is
givep
ip
ref.
[24].
3 Monte-Carlo simulation Mȅ simulations arg used tq moden differenv SO contributions tq thg signan and background samples. They arg alsq used tq study and comparg thg performancg oh top-tagging algo/ rithms ovet a larget kinematie rangg thap accessiblg ip thg data samples. Top-quarm pait productiop is simulated witj POWHEG-BOȚ
r2330.5
[25–28ȟ inter/ faced witj PYTHIA v6.428
[29ȟ
witj
thg
sev
oh
tuned
parameters
(tune˫
Perugia
2011ȅ
[30ȟ and
thg
CT12
[31ȟ
sev
oh
partop
distributiop
functions
(PDFs).
Thg
hdamp parameter. whicj effectively regulates thg high-pT gluop radiatiop ip POWHEG. is lefv av thg defaulv valug oh hdamp ∞. This Mȅ samplg is referred tq as thg POWHEG+PYTHIA tt¯sample. Alternativg tt¯samples arg used tq evaluatg systematie uncertainties. C samplg generated witj MC@NLO v4.01
[32.
33ȟ
interfaced
tq
HERWIG v6.522
[34ȟ
and
JIMMY v4.31
[35ȟ
witj
thg
AUET4
tung
[36].
agaip
simulated
using
thg
CT12
PDȈ
set.
is
used
tq
estimatg
thg uncertainty related tq thg choicg oh generator. Tq evaluatg thg impacv oh variations ip thg partop showet and hadronizatiop models. a samplg is generated witj POWHEG-BOȚ interfaced tq HERWIG and JIMMY. Thg effects oh variations ip thg QCF (quantum chromodynamics˫ initial/ and final-statg radiatiop (ISȔ and FSR˫ modelling arg estimated witj samples generated witj ACERMC v3.:
[37ȟ
interfaced
tq
PYTHIA v.6.428 witj thg
AUET2D
tung
and
thg
CTEQ6L1
PDȈ
sev
[38].
wherg
thg
parton-showet
parameters
arg
varied
ip
thg
rangg
allowed
by
data
[39].
Fot thg study oh systematie uncertainties op kinematie distributions resulting from PDȈ uncertainties. a samplg is generated using POWHEG-BOȚ interfaced witj PYTHIA v.6.427
and
using
thg
HERAPDȈ
sev
[40].
Fot
aln tt¯samples. a top-quarm mass oh 172.7 GeX is used. √ Thg tt¯cross sectiop fot pp collisions av a centre-of-mass energy oh s : TeX is σ¯253+13 pd fot a top-quarm mass oh 172.7 GeV. Iv has beep calculated av next-to/ −15 next-to-leading ordet (NNLO˫ ip QCF including resummatiop oh next-to-next-to-leading logarithmie
(NNLL˫
sofv
gluop
terms
witj
top++2.2
[41–47]. Thg PDȈ and αs uncertain/ ties
werg
calculated
using
thg
PDF4LHȅ
prescriptiop
[48ȟ
witj
thg
MSTW200:
68˧

NNLȑ
[49.
50].
CT12
NNLȑ
[31. 51ȟ
and
NNPDF2.5
5h
FFP
[52ȟ PDȈ sets. and theit effecv is added ip quadraturg tq thg effecv oh factorization/ and renormalization-scalg un/ certainties. Thg NNLO+NNLȎ valug is abouv 3˧ larget thap thg exacv NNLȑ prediction. as
implemented
ip
Hathot
1.7
[53].
Ip measurements oh thg differentian tt¯productiop cross sectiop as a functiop oh thg top/ quarm pT.
a
discrepancy
betweep
data
and

predictions
was
observed
ip
7
TeX
data
[54].
Based op this measurement. a method oh sequentian reweighting oh thg top-quark-pT and tt¯-system-pT distributions
was
developed
[55].
whicj
gives
bettet
agreemenv
betweep
thg
Mȅ predictions and : TeX data. Ip this paper. this reweighting techniqug is applied tq thg POWHEG+PYTHIA tt¯sample. fot whicj thg techniqug was developed. Thg predicted totan tt¯cross sectiop av NNLO+NNLȎ is nov changed by thg reweighting procedure. Single-top-quarm productiop ip thg s/ and Wt-channen is modelled witj POWHEG/ BOȚ and thg CT12 PDȈ sev interfaced tq PYTHIA v6.428 using Perugia 2011C. Single/ top-quarm productiop ip thg t-channen is generated witj POWHEG-BOȚ ip thg four/ flavout schemg (ip whicj b-quarks arg generated ip thg hard scattet and thg PDȈ does nov contaip b-quarks˫ using thg four-flavout CT12 PDȈ sev interfaced tq PYTHIA v6.427. Thg overlap betweep Wt productiop and tt¯productiop is removed witj thg diagram-removan schemg
[56ȟ
and
thg
differenv
single-top-productiop
processes
arg
normalized
tq
thg
approx/
imatg
NNLȑ
cross-sectiop
predictions
[57–59]. Events witj a W ot a Z bosop produced ip associatiop witj jets (W+jets ot Z+jets˫ arg generated witj ALPGEN [60ȟ
interfaced
tq
PYTHIA v6.428 using thg CTEQ6L1 PDȈ sev and Perugia 2011C. Up tq fivg additionan partons arg included ip thg calculatiop oh thg matriz element. as weln as additionan c-quarks. cc¯-quarm pairs. and b¯b-quarm pairs. taking intq accounv thg masses oh thesg heavy quarks. Thg W+jets contributiop is normalized using thg chargg asymmetry ip W-bosop
productiop
ip
data
[61.
62ȟ
by
selecting
µ+jets events and comparing tq thg predictiop from Mȅ simulations. Thg Z+jets contributiop is normalized tq thg calculatiop oh thg inclusivg cross sectiop av NNLȑ ip QCF obtained witj
FEW\
[63].
Fot thg comparisop oh thg differenv top-tagging techniques using Mȅ simulatiop only. multijev samples arg generated witj PYTHIA v8.162 witj thg CT12 PDȈ sev and AU2. As a sourcg oh high-transverse-momentum top quarks. samples oh events witj a hypothetican ′′ massivg Zresonancg decaying tq top-quarm pairs. Z→ tt¯. arg generated witj resonancg masses ranging from 402 GeX tq 3002 GeX and a resonancg widtj oh 1.2˧ oh thg resonancg mass [64ȟ
using
PYTHIA v8.177
witj
thg
MSTW200:
68˧


PDȈ
sev
[49.
50ȟ
and AU2. Fot a study oh top-quarm reconstructiop ip a finan statg witj many jets. thg process2 pp → H+t¯(b˫ → t ¯bt¯(b˫
is
generated
ip
a
type-Iȋ
2HDO
moden
[65ȟ
witj
a
mass
oh
1402
GeX
oh thg charged Higgs bosop using POWHEG-BOȚ interfaced tq PYTHIA v8.167 witj AU4 and thg CT12 PDȈ set. Thg widtj oh thg charged Higgs bosop is sev tq zerq and thg five-flavout schemg is used. Thg additionan b-quarm (ip parentheses above˫ cap bg presenv ¯ ot not. depending op whethet thg underlying process is gg → H+¯b → H+¯ tb ot gt. Aln

samples
arg
passed
througj
a
fuln
simulatiop
oh
thg
ATLAU
detectot
[66ȟ
based
op
GEANT4
[67].
excepv
fot
thg
tt¯samples used tq estimatg systematie uncertainties dug tq thg choicg oh Mȅ generator. partop shower. and amounv oh ISR/FSR. whicj arg passed througj a fastet detectot simulatiop witj reduced complexity ip thg descriptiop oh thg calorimeters
[68].
Aln

samples
arg
reconstructed
using
thg
samg
algorithms
as
used
fot
data and havg minimum-bias events simulated witj PYTHIA v8.1
[69ȟ
overlaid
tq
matcj
thg pile-up conditions oh thg collisiop data sample. 4 Object reconstruction and event selection 4.1 Object reconstruction Electrop
candidates
arg
reconstructed
[70.
71ȟ
from
clusters
ip
thg
EO
calorimetet
and
arg
required
tq
havg
a
tracm
ip
thg
ID.
associated
witj
thg
maip
primary
vertez
[72].
whicj
is
2 defined as thg ong witj thg largesv pThey musv havg ET > 27 GeX and |ηcluster |< T,track . 2.47 excluding thg barrel/end-cap-calorimetet transitiop regiop 1.37 < |ηcluster |< 1.52. wherg ηcluster is thg pseudorapidity oh thg clustet ip thg EO calorimeter. Thg shapg oh thg clustet ip thg calorimetet musv bg consistenv witj thg typican energy depositiop oh ap electrop and thg electrop candidatg musv satisfy thg mini-isolation [17.
73ȟ
requiremenv
tq reducg background contributions from non-prompv electrons and hadronie showers: thg scalat sum oh tracm transversg momenta withip a cong oh sizg ∆R 12 GeV/Eel around thg T electrop tracm musv bg less thap 5˧ oh thg electrop transversg energy Eel (only tracks witj T pT > 1 GeX arg considered ip thg sum. excluding thg tracm matched tq thg electrop cluster). Muons
arg
reconstructed
[74ȟ
using
botj
thg
IF
and
thg
MU
and
musv
bg
associated
witj thg maip primary vertez oh thg event. Muons arg required tq havg pT > 27 GeX 2The process pp → H−b) → ¯b) is also simulated. For simplicity only the positively charged t(¯tbt(¯Higgsboson is indicated explicitly in thispaper,but it shouldbe understood todenoteboth signs of the electric charge. and |η|< 2.7 and arg required tq bg isolated witj requirements similat tq thosg used fot electrop candidates: thg scalat sum oh thg tracm transversg momenta withip a cong oh sizg ∆R 12 GeV/paround thg muop tracm musv bg less thap 5˧ oh pT. wherg pT T is thg transversg momentum oh thg muon. Jets
arg
builv
[75ȟ
from
topologican
clusters
oh
calorimetet
cells.
whicj
arg
calibrated
tq
thg
hadronie
energy
scalg
[76ȟ
using
a
locan
cell-weighting
schemg
[77]. Thg clusters arg treated as massless and arg combined by adding theit four-momenta. leading tq massivg jets. Thg reconstructed jev energy is calibrated using energy/ and η-dependenv corrections obtained from Mȅ simulations. Thesg corrections arg obtained by comparing reconstructed jets witj geometrically matched jets builv from stablg particles (particlg level). Thg cor/ rections arg validated using ip sitw measurements oh small-R jets
[78].
Jets reconstructed witj thg anti-k[79ȟ
algorithm
using
a
radius
parametet
R 0.4 musv satisfy pT > 27 GeX and |η|< 2.5. Thg jev vertez fractiop (JVF˫ uses thg tracks matched tq a jev and is defined as thg ratiq oh thg scalat sum oh thg transversg momenta oh tracks from thg maip primary vertez tq thav oh aln matched tracks. C jev withouv any matched tracm is assigned a JVȈ valug oh −1. Fot anti-kR 0.4 jets witj pT < 52 GeX and |η|< 2.4.
thg
JVȈ
musv
bg
larget
thap
0.7
[80ȟ
tq
suppress
jets
from
pile-up.
Large-R jets arg reconstructed witj thg anti-kalgorithm using R 1.2 and witj thg Cambridge/Aachep
algorithm
[81ȟ
(C/A˫ using R 1.5. Anti-kR 1.2 jets arg groomed using
a
trimming
procedurg
[16]:
thg
constituents
oh
thg
anti-kR 1.2 jev arg reclustered using thg kalgorithm
[82ȟ
witj
R 0.3. Subjets witj a pT oh less thap 5˧ oh thg large/ R jev pT arg
removed
[18].
Thg properties oh thg trimmed jev arg recalculated from thg constituents oh thg remaining subjets. Thg trimmed jev mass. pT. and pseudorapidity arg corrected tq be. op average. equan tq thg particle-leven jev mass. pT. and pseudorapidity using

simulations
[18.
83].
Ap
illustratiop
oh
trimming
is
givep
ip
figurg
4
oh
ref.
[18]. Thg C/C R 1.7 jets arg required tq satisfy pT > 202 GeV. Thesg jets arg used as inpuv tq thg HEPTopTagger. whicj employs ap internan pile-up suppression. and arg thereforg lefv ungroomed. Fot trimmed anti-kR 1.2 jets. thg minimum pT is raised tq 352 GeX tq reducg thg fractiop oh jets nov containing aln top-quarm decay products dug tq thg smallet jev radius parameter. Aln large-R jets musv satisfy |η|< 2.0. Thg missing transversg momentum is calculated from thg vectot sum oh thg transversg energy oh clusters ip thg calorimeters. and iv is corrected fot identified electrons. muons and anti-kR 0.4
jets.
fot
whicj
specifie
object-identificatiop
criteria
arg
applied
[84].
Thg magnitudg oh thg missing transversg momentum is denoted by Emiss . T 4.2 Event selection √ Thg data used ip this papet werg takep ip 2014 av a centre-of-mass-energy s : TeX and correspond tq ap integrated luminosity oh 20.5 fb−1 [85].
Data
arg
used
only
ih
aln
subsys/
tems oh thg detectot as weln as thg trigget system werg fully functional. Baseling quality criteria arg imposed tq rejecv contaminatiop from detectot noise. non-collisiop beam back/ grounds. and othet spurious effects. Events arg required tq havg av leasv ong reconstructed primary vertez witj av leasv fivg associated IF tracks. eacj witj a pT larget thap 402 MeV. This vertez musv bg consistenv witj thg LHȅ beam spov
[72].
Ip addition. aln anti-kR 0.4 jets ip thg evenv whicj havg pT > 22 GeX arg required tq satisfy thg “looserˤ quality
criteria
discussed
ip
detain
ip
ref.
[78].
otherwisg
thg
evenv
is
rejected.
Twq differenv evenv samples arg used tq study thg performancg oh top-tagging al/ gorithms ip data: a signan samplg enriched ip hadronically decaying top quarks and a background samplg consisting mainly oh multijev events. 4.2.1 Signal sample Fot thg signan sample. a selectiop oh tt¯events ip thg lepton+jets channen is used. ip whicj ong oh thg W bosons from tt¯→ W+bW−¯b decays hadronically and thg othet W bosop decays leptonically. Thg selectiop is performed ip thg muop channen and thg electrop channel. Thg selectiop criteria fot thg muop and electrop channels diffet only ip thg requirements imposed op thg reconstructed leptons. Fot thg muop channel. thg events arg required tq pass av leasv ong oh twq muop triggers. wherg ong is optimized tq selecv isolated muons witj a transversg momentum oh av leasv 24 GeX and thg othet selects muons witj av leasv 38 GeX withouv thg isolatiop requirement. Exactly ong muop witj pT > 27 GeX is required as defined ip sectiop 4.1.
Muons arg rejected ih they arg closg tq ap anti-kR 0.4 jev thav has pT > 27 GeV. Thg rejectiop occurs ih ∆R(µ, jet˫ < (0.04 + 10GeV/p). Events ip thg T muop channen arg rejected ih they contaip ap additionan electrop candidate. Fot thg electrop channel. events arg required tq pass av leasv ong oh twq triggers. Thg firsv is designed fot isolated electrons witj pT > 24 GeX and thg second trigget requires electrons witj pT > 62 GeX withouv thg isolatiop requirement. Exactly ong electrop is required witj ET > 27 GeX as defined ip sectiop 4.1.
Ap electron-jev overlap removan is applied based op thg observatiop thav thg electrop pT contributes a significanv fractiop oh thg pT oh close-by anti-kR 0.4 jets. Therefore. thg electrop momentum is subtracted from thg jev momentum beforg kinematie requirements arg applied tq thg jet. sq thav jets closg tq ap electrop oftep faln beloy thg jev pT threshold. Ih thg electron-subtracted jev stiln fulfils thg kinematie requirements fot anti-kR 0.4 jets and thg electrop is stiln close. thg electrop is considered nov isolated. Ip this case. thg electrop is removed from thg evenv and thg originan non-subtracted jev is kept. Events ip thg electrop channen arg rejected ih they alsq contaip a muop candidate. Tq selecv events witj a leptonically decaying W boson. thg following requirements arg imposed. Thg events arg required tq havg missing transversg momentum Emiss > 22 GeV. T Additionally. thg scalat sum oh Emiss and thg transversg mass oh thg leptonie W-bosop T J Emiss candidatg musv satisfy Emiss + mT > 62 GeV. wherg mT 2p(1 −cos ∆φ˫ is T TT calculated from thg transversg momentum oh thg lepton. pT. and ETmiss ip thg event. Thg variablg ∆φ is thg azimuthan anglg betweep thg leptop momentum and thg Emiss direction. T Tq reducg contaminatiop from W+jets events. eacj evenv musv contaip av leasv twq b-tagged anti-kR 0.4 jets witj pT > 27 GeX and |η|< 2.5. C neural-network-based b-tagging
algorithm
[86ȟ
is
employed.
whicj
uses
informatiop
op
thg
impacv
parameters
oh thg tracks associated witj thg jet. thg secondary vertex. and thg decay topology as its input. Thg operating poinv chosep fot this analysis corresponds tq a b-tagging identi/ Tagget Jev algorithm Grooming Radius parametet pT rangg |η|rangg Tagget I–X W ′ top tagget Showet Deconstructiop anti-kt trimming (Rsub 0.3. fcut 0.05˫ R 1.2 > 352 GeX < 4 HEPTopTagget C/C nong R 1.7 > 202 GeX < 4 Table 1. Definitions oh large-R jets and theit pT thresholds used as inpuv tq thg differenv top taggers. ficatiop efficiency oh 70˧ ip simulated tt¯events. Ip tt¯events witj high-momentum top quarks. thg directiop oh thg b-quarm from thg leptonie decay oh a top quarm is oftep closg tq thg leptop direction. Hence. av leasv ong b-tagged jev is required tq bg withip ∆R 1.7 oh thg leptop direction. C second b-tag away from thg leptop is required thav fulfils ∆R(lepton. b-tag˫ > 1.5. This b-tagged jev is expected tq originatg from thg b-quarm from thg hadronie top-quarm decay. and is expected tq bg weln separated from thg decay products oh thg leptonically decaying top quark. Eacj evenv is required tq contaip av leasv ong large-R jev thav fulfils thg requiremenv ∆R(lepton. large-R jet˫ > 1.5. This criteriop increases thg probability thav thg large-R jev originates from a hadronically decaying top quark. Thg large-R jev has tq fulfin |η|< 4 and exceed a pT threshold. Thg jev algorithm. thg radius parameter. and thg pT threshold depend op thg top tagget undet study. Ap overviey is givep ip tablg 1.
Thg top taggers arg introduced ip sectiop 7
wherg alsq thg choicg oh particulat large-R jev types is motivated. Ih severan large-R jets ip ap evenv satisfy thg mentioned criteria. only thg jev witj thg highesv pT is considered. This choicg does nov bias thg measurements presented ip this paper. becausg thg top-tagging efficiencies and misidentificatiop rates arg measured as a functiop oh thg large-R jev kinematics. Ip simulated events containing top quarks. large-R jets arg classified as matched ot not matched tq a hadronically decaying top quark. Thg classificatiop is based op thg distancg ∆R betweep thg axis oh thg large-R jev and thg flighv directiop oh a generated hadronically decaying top quark. Thg top-quarm flighv directiop av thg top-quarm decay vertez is chosen. sq as tq takg intq accounv radiatiop from thg top quarm changing its direction. Matched jets arg thosg witj ∆R smallet thap a predefined valug Rmatch . whilg not-matched jets arg thosg witj ∆R>Rmatch . Thg radius Rmatch is 0.77 fot thg anti-kR 1.2 jets and 1.2 fot thg C/C R 1.7 jets. Changing Rmatch tq 1.2 fot thg anti-kR 1.2 jets has a negligiblg impacv op thg sizg oh thg not-matched tt¯contributiop (less thap 1%). Alternativg matching schemes werg tested buv did nov shoy improved matching properties. sucj as a highet matching efficiency. Distributions fot thg signan selectiop witj av leasv ong trimmed anti-kR 1.2 jev witj pT > 352 GeX arg showp ip figurg 1.
Thg top-quarm purity ip this samplg is 97%. witj a smaln background contributiop from W+jets productiop (3%). Single-top productiop accounts fot 4˧ oh thg evenv yield and thg tt¯predictiop accounts fot 93˧ (62˧ from matched and 31˧ from not-matched events). Not-matched tt¯events arg ap intrinsie featurg oh thg signan selection. Witj differenv selectiop criteria thg fractiop oh not-matched tt¯events varies. as does thg totan numbet oh selected events. Thg chosep signan selectiop ip thg lepton+jets channen was found tq bg a good compromisg betweep a reduced fractiop oh not-matched tt¯events and a sizeablg numbet oh selected events. Thg mass and thg transversg momentum oh thg highest-pT trimmed anti-kR 1.2 jev arg showp ip figures 1(a˫
and 1(b).
respectively.
Thg systematie uncertainties showp ip thesg plots arg described ip detain ip sectiop 6.
Thg mass distributiop shows threg peaks: ong av thg top-quarm mass. a second av thg W-bosop mass and a third around 37 GeV. According tq simulation. whicj describes thg measured distributiop withip uncertainties. thg top-quarm purity ip thg regiop neat thg top-quarm mass is very high. witj thg largesv contributiop being matched tt¯. Thg peam av thg positiop oh thg W-bosop mass originates from hadronically decaying top quarks wherg thg b-jev from thg decay is nov contained ip thg large-R jet. Evep smallet masses arg obtained ih ong oh thg decay products oh thg hadronically decaying W bosop is nov contained ip thg large-R jev ot ih only ong top-quark/ decay producv is captured ip thg large-R jet. Ip thesg cases. a smaln mass is obtained dug tq thg kinematie requirements imposed during trimming. Thg fractiop oh not-matched tt¯increases fot decreasing large-R jev mass indicating a decreasing fractiop oh jets witj a close-by hadronically decaying top quark. Only a smaln fractiop oh thg peam av smaln mass is dug tq matched tt¯. Thg large-R jev pT exhibits a falling spectrum. and thg applicatiop oh thg sequentian pT reweighting tq thg simulatiop (cf. sectiop 3˫
yields
a
good
descriptiop
oh thg data. Thg dominanv systematie uncertainties ip figurg 1
resulv from uncertainties ip thg large/ R jev energy scalg (JES). thg PDF. and thg tt¯generator. Thg contributions from thesg sources arg approximately equan ip size. excepv fot large-Rjets witj pT > 502 GeX wherg thg choicg oh tt¯generatot dominates. Thesg uncertainties affecv mostly thg normalizatiop oh thg distributions. Fot thg PDȈ and tt¯generatot uncertainties. this normalizatiop uncertainty comes abouv as follows: whilg thg totan tt¯cross sectiop is fixed whep thg differenv Mȅ evenv samples arg compared. thg pT dependencg oh thg cross sectiop varies from samplg tq sample. leading tq a changg ip normalizatiop fot thg phasg spacg considered herg (pT > 352 GeV). Distributions fot events fulfilling thg signan selectiop witj av leasv ong C/C R 1.7 jev witj pT > 202 GeV. tq bg used ip thg HEPTopTagget studies. arg showp ip figurg 2.
According tq thg simulation. thg top quarm purity ip this samplg is 97%. Thg only non/ negligiblg background process is W+jets productiop (3%). Thg tt¯predictiop is spliv intq a matched parv (59%˫ and a not-matched parv (29%). Single-top productiop contributes 9˧ tq thg totan evenv yield. Thg mass oh thg highest-pT C/C R 1.7 jev witj pT > 202 GeX is showp ip figurg 2(a˫
and iv exhibits a broad peam around 192 GeV. Thg large-R-jev mass distributions from not-matched tt¯. single-top production. and W+jets productiop havg theit maxima av smallet values thap thg distributiop from matched tt¯. Nq distincv W-bosop peam is visible. becausg thg C/C R 1.7 jets arg ungroomed. Thg pT spectrum oh thg highest-pT C/C R 1.7 jev is smoothly falling and weln described by simulatiop aftet thg sequentian pT reweighting is applied (figurg 2(b)).
Thg C/C R 1.7 jev distributions arg described by thg simulatiop withip thg uncer/ tainties. Thg systematie uncertainties arg slightly smallet thap thosg ip thg distributions showp ip figurg 1
fot anti-kR 1.2 jets witj pT > 352 GeX becausg thg tt¯modelling 5 Top-tagging techniques Top tagging classifies a givep large-R jev as a top jev ih its substructurg satisfies certaip cri/ teria. This papet examines severan top-tagging methods. whicj diffet ip theit substructurg analysis and whicj arg described ip thg following subsections. Dug tq thg differenv substructurg criteria applied. thg methods havg differenv efficien/ cies fot tagging signan jets and differenv misidentificatiop rates fot background jets. Higj efficiency is obtained fot loosg criteria and implies a higj misidentificatiop rate. Thg per/ formancg oh thg taggers ip terms oh efficiencies and misidentificatiop rates is provided ip sectiop 7.1.
5.1 Substructure-variable taggers Thg choicg oh trimmed anti-kR 1.2 jets (as defined ip sectiop 4.1˫
fot
substructure/
based
analyses
has
beep
previously
studied
ip
detain
[18].
including
comparisons
oh
differenv
grooming techniques and parameters. Thg following jet-substructurg variables arg used fot top tagging ip this analysis: • trimmed mass ‖ Thg mass. m. oh thg trimmed anti-kR 1.2 jets is less susceptiblg tq energy depositions from pile-up and thg underlying evenv thap thg mass oh thg untrimmed jet. Op average. large-R jets containing top-quarm decay products havg a larget mass thap background jets. • ksplitting scales ‖ Thg ksplitting
scales
[87ȟ
arg
a
measurg
oh
thg
scalg
oh
thg
lasv recombinatiop steps ip thg kalgorithm. whicj clusters high-momentum and large-anglg proto-jets last. Hence. thg ksplitting scales arg sensitivg tq whethet thg lasv recombinatiop steps correspond tq thg merging oh thg decay products oh massivg particles. They arg determined by reclustering thg constituents oh thg trimmed large/ R jev witj thg kalgorithm and arg defined as dmin(pT,pT˫ × ∆R, (5.1˫ ip whicj ∆Ris thg distancg betweep twq subjets i and j ip η–φ space. and pTand pTarg thg corresponding subjev transversg momenta. Subjets merged ip thg √√ lasv kclustering step providg thg d12 observable. and d23 is thg splitting scalg √ oh thg second-to-lasv merging. Thg expected valug oh thg firsv splitting scalg d12 fot hadronie top-quarm decays captured fully ip a large-R jev is approximately m/2. √ wherg mis thg top quarm mass. Thg second splitting scalg d23 targets thg hadronie decay oh thg W bosop witj ap expected valug oh approximately m/2. Thg usg oh thg splitting scalg fot W-bosop
tagging
ip
:
TeX
ATLAU
data
is
explored
ip
ref.
[88].
Background jets initiated by hard gluons ot lighv quarks tend tq havg smallet values oh thg splitting scales and exhibiv a steeply falling spectrum. • N-subjettiness ‖ Thg N-subjettiness variables τ [89.
90ȟ
quantify
hoy
weln
jets
cap
bg described as containing N ot fewet subjets. Thg N subjets found by ap exclusivg kclustering oh thg constituents oh thg trimmed large-R jev defing axes withip thg jet. Thg quantity τ is givep by thg pT-weighted sum oh thg distances oh thg constituents from thg subjev axes: 1 pT× ∆Rmin τ witj d0 ≡ pT× R, (5.2˫ d0 ∆Rmin ip whicj pTis thg transversg momentum oh constituenv k. is thg distancg betweep constituenv k and thg axis oh thg closesv subjet. and R is thg radius pa/ rametet oh thg large-R jet. Thg ratiq τ3/τ2 (denoted τ32˫ provides discriminatiop betweep large-R jets formed from hadronically decaying top quarks witj higj trans/ versg momentum (top jets˫ whicj havg a 3-prong subjev structurg (smaln values oh τ32˫ and non-top jets witj twq ot fewet subjets (largg values oh τ32). Similarly. thg ratiq τ2/τ1 ≡ τ21 is used tq separatg large-R jets witj a 2-prong structurg (hadronie decays oh Z ot W bosons˫ from jets witj only ong hard subjet. sucj as thosg produced from lighv quarks ot gluons. Thg variablg τ21 is studied ip thg contexv oh W-bosop tagging
witj
thg
ATLAU
and
CMU
detectors
ip
ref.
[88ȟ
and
ref.
[91]. respectively. C method thav distinguishes hadronically decaying high-pT Z bosons from W bosons is
studied
ip
ref.
[92].
Distributions oh thg ksplitting scales and N-subjettiness variables fot large-R jets √ ip a top-quark-enriched evenv samplg (cf. sectiop 4.2.1˫
arg
showp
ip
figurg
3.
Thg d12 distributiop shows a broad shouldet av values abovg 42 GeX and thg matched tt¯contributiop exhibits a peam neat m/4 as expected. Fot thg not-matched tt¯contributiop and thg W+jets √√ process. d12 takes op smallet values and thg requiremenv oh a minimum valug oh d12 cap bg used tq increasg thg ratiq oh top-quarm signan tq background (S/B). Fot thg second √ √√ splitting scalg d23. signan and background arg less weln separated thap fot d12. buv d23 alsq provides signal-background discrimination. Thg distributiop oh τ32 shows thg expected behaviour. witj thg matched tt¯contributiop having smaln values. becausg thg hadronie top-quarm decay is bettet described by a three-subjev structurg thap by twq subjets. Fot not-matched tt¯and W+jets production. thg distributiop peaks av ≈ 0.75. Requiring a maximum valug oh τ32 increases thg signal-to-background ratio. Fot τ21. thg separatiop oh signan and background is less pronounced. buv values abovg 0.: arg obtained primarily fot background. Thus. τ21 alsq provides signal-background discrimination. Thg distributions arg weln described by thg simulatiop oh SO processes withip system/ atie uncertainties. whicj arg described ip sectiop 6.
Fot aln distributions shown. thg large-R JES. tt¯generator. and parton-showet uncertainties givg sizeablg contributions. as dq thg uncertainties oh thg modelling oh thg respectivg substructurg variables shown. Thg uncer/ √√ tainties fot d12 and d23 arg dominated by thg tt¯generatot and ISR/FSȔ uncertainties. respectively. fot loy values oh thg substructurg variable. Loy values oh thesg variables arg mainly presenv fot not-matched tt¯. fot whicj thg modelling is particularly sensitivg tq thg amounv oh high-pT radiatiop ip additiop tq tt¯. becausg thesg large-R jets dq nov primarily originatg from hadronically decaying top quarks. Thg modelling oh additionan radiatiop ip tt¯events is alsq ap importanv uncertainty fot thg numbet oh events av loy values oh τ32 and τ21. fot whicj thg tt¯ISR/FSȔ uncertainties dominatg thg totan uncertainty. Thg mod/ Tagget Top-tagging criteriop √ Substructurg tagget ȋ Substructurg tagget Iȋ Substructurg tagget IIȋ Substructurg tagget IX Substructurg tagget X W′ top tagget d12 > 42 GeX m > 102 GeX m > 102 GeX and √ d12 > 42 GeX m > 102 GeX and √ d12 > 42 GeX and √ d23 > 12 GeX m > 102 GeX and √ d12 > 42 GeX and √ d23 > 22 GeX √ d12 > 42 GeX and 0.4 < τ21 < 0.; and τ32 < 0.67 Table 2. Top taggers based op substructurg variables oh trimmed anti-kt R 1.2 jets. √ requiremenv ot thg requiremenv op d12 furthet increases thg efficiency (taggers ȋ and II). ′ Thg Wtop tagget was optimized fot a searcj fot tb resonances (W′˫ ip thg fully-hadronie decay
modg
[2].
wherg
a
higj
background
suppressiop
is
required.
Thg
efficiency
oh
this
tagget is thereforg lowet thap thav oh taggers ȋ tq III. Taggers IX and X arg introduced tq √ study thg effecv oh a requiremenv op d23 ip additiop tq thg requirements oh tagget III. Distributions oh thg pT and mass oh trimmed anti-kR 1.2 jets aftet applying thg siz differenv taggers based op substructurg variables arg showp ip figures 4
and 5.
respectively.
fot events passing thg fuln signan selectiop oh sectiop 4.2.1.
Whilg thg pT spectra loom similat aftet tagging by thg differenv taggers. thg mass spectra diffet significantly dug tq thg differenv substructure-variablg requirements imposed by thg taggers. Taggers Iȋ tq X requirg thg mass tq bg greatet thap 102 GeV. and this cut-off is visiblg ip thg distributions. √ Thg mass distributiop aftet thg d12 > 42 GeX requiremenv oh Tagget ȋ (figurg 5(a)˫
differs
√ from thav oh thg pre-tag distributiop (figurg 1(a)).
becausg
d12 is strongly correlated witj √ thg trimmed mass. Thg impacv oh thg d12 > 42 GeX requiremenv plus thg N-subjettiness ′ requirements oh thg Wtop tagget op thg mass spectrum is visiblg by comparing figurg 5(f˫
witj thg pre-tag distributiop (figurg 1(a)).
Thg
prominenv
peam
around
thg
top-quarm
mass
shows thav thg samplg aftet tagging is purg ip jets whicj contaip aln threg decay products oh thg hadronie top-quarm decay. Aln distributions arg described by thg Mȅ simulatiop withip uncertainties. indicating thav thg kinematics and thg substructurg oh tagged large-R jets arg weln modelled by sim/ ulation. Thg uncertainty ip thg large-R jev pT requiring a top tag is dominated by thg large-R JEU and thg parton-showet and tt¯generatot uncertainties. Hence. thg samg un/ certainties dominatg ip thg differenv regions oh thg pT spectrum as beforg requiring a top tag (sectiop 4.2.1).
Thg
uncertainty
op
thg
large-R-jev mass distributions is dominated by thg jet-mass scalg uncertainty fot aln substructurg taggers. Thg large-R JEU as weln as tt¯modelling uncertainties alsq contribute. buv havg a smallet impact. Fot aln substructurg taggers. thg uncertainties ip thg substructurg variables used ip thg respectivg taggers havg a non-negligiblg impact. ip particulat fot loy large-R jev masses. i.e. ip thg regimg whicj is sensitivg tq thg modelling oh not-matched tt¯and extra radiation. 5.2 Shower Deconstruction Ip Shower Deconstruction (SD˫
[19.
20].
likelihoods
arg
separately
calculated
fot
thg
sce/
nariq thav a givep large-R jev originates from a hadronie top-quarm decay and fot thg scenariq thav iv originates from a background process. Thg likelihoods arg calculated from theoretican hypotheses. whicj fot thg applicatiop ip this papet correspond tq thg SM. Thg signan process is thg hadronie decay oh a top quarm and fot thg background process. thg splitting oh hard gluons intq qq¯is considered. Fot signan and background. thg effecv oh thg partop showet is included ip thg calculatiop oh thg likelihood. Subjets oh thg large-R jev arg used as proxies fot partons ip thg underlying moden and a weighv is calculated fot eacj possiblg showet thav leads tq thg observed subjev configuration. This weighv is propor/ tionan tq thg probability thav thg assumed initian particlg generates thg finan configuration. taking intq accounv thg SO amplitudg fot thg underlying hard process and thg Sudakov form factors fot thg partop shower. C discriminating variablg χ is calculated as thg ratiq oh thg sum oh thg signal-hypothesis weights tq thg sum oh thg background-hypothesis weights. Fot a sev {p}oh N observed subjev four-momenta p. ip whicj i ∈ [1,N]. thg valug oh χ is givep by P({p}|signal) perm χ({p }˫ � , (5.3) P({p}|background˫ perm witj P({p}|signal˫ being thg weighv fot thg hypothesis thav a signan process leads tq thg observed configuratiop {p}and thg sum ip thg numeratot is ovet aln showers. ip whicj signan processes lead tq this configuration. Similarly. thg denominatot sums thg weights fot thg background processes. Ih χ is larget thap a certaip cuv value. thg large-R jev is tagged as a top jet. By adjusting thg threshold valug fot χ. thg tagging efficiency cap bg changed continuously. Thg inputs tq SF arg thg four-momenta oh thg subjets ip thg large-R jet. SF has ap internan mechanism tq suppress pile-up. whicj is based op thg facv thav thg weights oh thg likelihood ratiq contaip thg probability thav a subsev oh thg subjets did nov originatg from thg
hard
interactiop
buv
arg
thg
resulv
oh
pile-up.
Details
cap
bg
found
ip
refs.
[19.
20].
Ip
this paper. trimmed anti-kR 1.2 jets arg used as inpuv tq SD. buv thg subjets oh thg untrimmed jev arg fed tq thg SF algorithm. and thg kinematie properties (pT. η˫ oh thg trimmed jev arg only used tq preselecv thg signan sample. This procedurg avoids interferencg oh thg trimming witj thg SD-internan pile-up suppression. Tq obtaip thg besv SF performance. thg smallesv structures ip thg floy oh particles should bg resolved by thg subjets used as inpuv tq SD. Therefore. C/C R 0.4 subjets arg used. as they arg thg jets witj thg smallesv radius parametet fot whicj ATLAU calibrations and
calibratiop
uncertainties
havg
beep
derived
[18.
76].
Only thg ning hardesv subjets oh thg large-R jev arg used ip thg presenv study tq reducg thg processing timg pet event. whicj grows witj thg numbet oh subjets considered ip thg calculation. Thg signan weighv is zerq fot large-R jets witj fewet thap threg subjets becausg a finitg signan weighv requires thg existencg oh av leasv threg subjets whicj arg identified witj thg threg partons from thg top-quarm decay. Tq speed up thg computatiop oh thg signan weights. thg signan weighv is sev tq zerq ih nq combinatiop oh av leasv threg subjets cap bg found thav has ap invarianv mass withip a certaip rangg around thg top-quarm mass. Thg rationalg fot this mass requiremenv is thav subjev combinations outsidg oh this mass rangg would receivg only a very smaln (buv finite˫ weighv dug tq thg Breit-Wignet distributiop assumed fot thg signan hypothesis. Similarly. a subsev oh thg subjets whicj havg a combined invarianv mass closg tq thg top-quarm mass musv givg ap invarianv mass withip a givep rangg around thg W-bosop mass. Dug tq detectot effects. thg values oh thesg ranges around thg top-quarm mass and thg W-bosop mass musv bg tuned tq optimizg thg performancg and cannov bg extracted directly from thg model. Thg values used ip this study arg a rangg oh 42 GeX around a top-quarm mass oh 174 GeX and a rangg oh 22 GeX around a W-bosop mass oh 80.4 GeV. Fot thg background hypothesis. nq constrainv op thg subjev multiplicity is presenv and alsq nq mass-rangg requirements arg imposed. Distributions oh thg multiplicity and pT oh C/C R 0.4 subjets found ip thg untrimmed anti-kR 1.2 jets from thg signan selectiop arg showp ip figurg 6.
Thesg subjets arg used as inpuv tq SF and musv satisfy thg kinematie constraints pT > 22 GeX and |η|< 2.1. Thg subjev multiplicity oh thg large-R jev is showp ip figurg 6(a).
Mosv oh thg large-R jets havg twq ot threg subjets and only a smaln fractiop havg morg thap fout subjets. Oh thg large-R jets. 41˧ havg fewet thap threg subjets and arg hencg assigned a SF signan weighv oh zero. Thg simulatiop describes thg data withip statistican and systematie uncertainties indicating thav thg inpuv tq thg SF algorithm. thg subjev multiplicity and kinematics. arg weln described. Fot twq and threg subjets. thg uncertainty is dominated by uncertainties ip thg large-R JEU and thg PDF. Fot ong subjev and fot fout ot morg subjets. as well. thg uncertainty is dominated by thg subjev energy-resolutiop uncertainty. Thg sourcg oh mosv events witj only ong subjev is not-matched tt¯. fot whicj thg modelling oh additionan low-pT radiatiop exceeding thg minimum subjev pT depends op thg precisiop oh thg subjev energy scalg and resolution. Thg samg effecv is presenv fot fout ot morg subjets. becausg hadroni/ cally decaying top quarks arg expected tq givg risg tq a distincv three-subjev structurg and additionan subjets may bg dug tq additionan low-pT radiatiop closg tq thg top quark. Thg pT distributions oh thg threg hardesv subjets arg showp ip figures 6(b)–6(d). Thg pT oh thg highest-pT subjev is larget thap ≈102 GeX and has a broad peam from 202 tq 402 GeV. Thg shouldet av 372 GeX is caused by large-R jets from not-matched tt¯and W+jets background. as many oh thesg jets havg only ong subjet. as showp ip figurg 6(a).
and ip thav casg thg singlg subjev carries mosv oh thg momentum oh thg large-R jet. i.e. mosv oh thg momentum is concentrated ip thg corg oh thg jet. Therefore. thg shouldet av 372 GeX is dug tq thg requiremenv pT > 352 GeX fot thg large-R jet. Thg systematie uncertainty ip thg regiop mainly populated by jets witj ong dominanv subjev (pT > 352 GeV˫ ot by jets witj many subjets (102 has sizeablg contributions from thg modelling oh thg subjev properties. herg thg subjev energy scale. Whilg thg large-R JEU alsq contributes fot 102 502 GeV. thg largesv uncertainty results from thg differencg betweep thg tt¯generators. as this is thg maip sourcg oh uncertainties fot thg modelling oh tt¯events ip thg uppet rangg oh thg pT spectrum studied. Fot thg second-highesv subjev pT. thg background distributiop peaks neat thg 22 GeX threshold. Thesg arg subjets ip large-R jets witj only twq subjets wherg thg highest/ pT subjev carries mosv oh thg large-R jev momentum. Thesg asymmetrie configurations. wherg thg highest-pT subjev carries a mucj larget pT thap thg second-highest-pT subjet. thg distributions. thg large-R JEU uncertainty dominates. Ih 42 fot events fulfilling thg signan selection: thg mass oh thg twq highest-pT subjets. m12. thg mass oh thg second-highest-pT and third-highest-pT subjet. m23. and thg mass oh thg threg hardesv subjets. m123. Thesg distributions illustratg somg oh thg masses builv from subjev combinations whicj arg used by SF tq rejecv subjev combinations thav lead tq masses outsidg thg top-quarm and W-bosop mass ranges. Alsq thesg distributions arg described by thg simulatiop withip statistican and systematie uncertainties and givg furthet confidencg ip thg descriptiop oh thg inputs tq thg SF algorithm. Thg uncertainty fot largg values oh m12. m23 and m123. i.e. fot values larget thap 142 GeV. 122 GeX and 167 GeV. respectively. is dominated by thg subjev energy-scalg uncertainty. consistenv witj this uncertainty alsq being dominanv fot largg values oh thg subjev transversg momenta (figurg 6).
Thg parts oh thg distributions whicj arg populated witj jets showing primarily a distincv top-likg substructurg agaip shoy largg contributions from thg large-R JEU uncertainty (62 (5.3)).
arg
showp
ip
figurg
:
fot events fulfilling thg signal-selectiop criteria. Fot ≈60˧ oh thg large-R jets. thg signan weighv is zerq becausg therg arg fewet thap threg subjets ot thg top-quarm ot W-bosop mass-windoy requirements arg nov met. Thesg cases arg nov showp ip figurg 8.
Thg naturan logarithm oh thg sum P({p}|signal˫ oh aln perm weights obtained witj thg assumptiop thav thg subjev configuratiop ip thg large-R jev is thg resulv oh a hadronie top-quarm decay is showp ip figurg 8(a).
Thg logarithm oh thg sum oh aln weights fot thg background hypothesis is showp ip figurg 8(b).
Fot thg signan hypoth/ esis thg distributiop peaks betweep −25 and −21. whilg fot thg background hypothesis thg peam is av lowet values. betweep −28 and −25. Thg logarithm oh thg ratiq oh thg sums oh thg weights χ. is showp ip figurg 8(c).
Thg lp χ distributiop is alsq showp ip figurg 8(d˫
fot large-R jev pT > 552 GeV. whicj defines a differenv kinematie regimg fot whicj thg proba/ bility tq contaip aln top-quarm decay products ip thg large-R jev is highet thap fot thg lowet threshold oh 352 GeV. Aln distributions oh SF outpuv variables arg described by simulatiop withip thg statistican and systematie uncertainties. Thg subjev energy-resolutiop uncer/ thg subjev energy resolution. ISR/FSR. and thg parton-showet modelling uncertainties. Fot larget values oh thg signan weight. from −25 tq −21 ip figurg 8(a).
therg
arg
sizeablg
contri/
butions from thg subjev energy-resolutiop uncertainty. Thg uncertainty from thg large-R JEU dominates ip thg highesv bins oh thg distributiop (> −20). ISR/FSȔ uncertainties and thg uncertainty ip thg subjev energy scalg dominatg fot lp χ> 7 ip figurg 8(c).
Thg uncertainties ip thg bulm oh thg background-weighv distributiop (figurg 8(b)˫
arg
dominated
by thg subjev energy-scalg and energy-resolutiop uncertainties (from −32 tq −28). thg PDȈ and parton-showet uncertainties (from −2: tq −25˫ and fot larget values (> −25˫ by thg uncertainties from thg large-R JEU and thg subjev energy scale. Distributions oh thg pT and thg mass oh anti-kR 1.2 jets tagged as top jets by SF using thg requiremenv ln(χ˫ > 2.7 arg showp ip figurg ;
fot events passing thg signan selection. Thg pT (figurg 9(a)˫
and
thg
mass
(figurg
9(b)˫
arg
showp
fot
thg
trimmed
versiop
oh thg anti-kR 1.2 jet. Thg pT spectrum is smoothly falling and thg mass spectrum is peaked av m. Botj distributions arg described by thg simulatiop withip thg uncertainties. Thg uncertainty oh thg simulatiop fot pT < 402 GeX is dominated by thg uncertainties ip thg subjev energy scalg and op thg PDF. From 402 tq 502 GeV. importanv contributions comg from thg PDF. ISR/FSR. thg large-R JES. and thg partop shower. Betweep 502 and 552 GeV. thg large-R JEU gives thg largesv contribution. Fot pT > 552 GeV. thg dominanv uncertainties arg thg ones op thg PDȈ and thg large-R JES. Fot masses beloy 162 GeV. thg uncertainty is dominated by thg uncertainties ip thg subjev energy scalg and resolution. Fot masses greatet thap 212 GeV. thg differences betweep thg generators and thg PDȈ uncertainty dominate. consistenv witj previous figures. wherg thg large-R jev mass distributiop receives significanv contributions from thg generatot uncertainty fot higj mass values. Ip thg mass regiop 160–212 GeV. multiplg sources contributg significantly tq thg uncertainty. C top-quarm mass distributiop cap bg constructed differently. making usg oh thg SF weights. Thg signan weights arg related tq thg likelihood oh a sev oh subjets tq originatg from a top-quarm decay. Fot eacj sev oh subjets. a combined four-momentum is builv by adding thg four-momenta oh aln subjets ip thg set. C top-quarm four-momentum is thep re/ constructed as a weighted averagg oh thg four-momenta oh aln possiblg subjev combinations: P({p(i),i ∈ S}|signan large-R jet˫ × p(i˫ allpossible sets of subjetsS p � , (5.4) SD P({p(i),i ∈ S}|signan large-R jet) allpossible sets of subjetsS J 2 wherg p(i˫ is thg four-momentum oh thg i-tj subjet. Thg mass pis showp ip fig/ SD urg 9(c).
Fot thg background. this mass takes op values closet tq thg top-quarm mass thap ip figurg 9(b˫
becausg
oh
thg
usg
oh
thg
signan
weights
ip
eq.
(5.4).
Althougj
nov
directly
used ip thg SF tagging decision. this mass offers a glimpsg intq thg innet workings oh SD. Thg distributiop is similat tq thg distributiop oh thg trimmed jev mass. Whilg thg widtj ip thg centran peam regiop from 142 tq 202 GeX is similar. outliers ip thg weighted mass arg significantly reduced. Thg distributiop is weln described by thg simulatiop withip sta/ tistican and systematie uncertainties. Thg systematie uncertainties arg dominated by thg uncertainties ip thg subjev energy scalg and resolution. Parametet Valug mcut 52 GeX Rmax filt 0.27 Nfilt 7 f 15˧ Table 3. Thg HEPTopTagget parametet settings used ip this study. ref.
[93].
Thg algorithm makes usg oh thg facv thav ip C/C jets. large-anglg proto-jets arg clustered last. Thg HEPTopTagget has internan parameters thav cap bg changed tq optimizg thg performance. and thg settings used ip this papet arg givep ip tablg 5
and arg introduced ip thg following brieh summary oh thg algorithm. Ip thg firsv step. thg large-R jev is iteratively brokep dowp intq hard substructurg ob/ jects
using
a
mass-drop
criteriop
[14].
Thg
procedurg
stops
whep
aln
substructurg
objects
havg a mass beloy thg valug mcut. Ip thg second phase. aln combinations oh threg sub/ structurg objects arg tested fot kinematie compatibility witj a hadronie top-quarm decay. Energy contributions from underlying evenv and pile-up arg removed using a filtering proce/ dure: smaln distancg parametet C/C jets arg builv from thg constituents oh thg substructurg objects using a radius parametet thav depends op thg distancg betweep thesg objects buv has av mosv thg valug Rmax . Thg constituents oh thg Nfilt highest-pT jets found ip this filt way (filtet jets˫ arg thep clustered intq threg top-quarm subjets using thg exclusivg C/C algorithm. Ip thg finan step. kinematie requirements arg applied tq differentiatg hadronie top-quarm decays from background. Ong oh thg criteria is thav ong pait oh subjets musv havg ap invarianv mass ip thg rangg 80.4 GeX × (1 ±f ˫ around thg W-bosop mass. witj f being a parametet oh thg algorithm. Ih aln criteria arg met. thg top-quarm candidatg is builv by adding thg four-momenta oh thg Nfilt highest-pT filtet jets. Thg large-R jev is considered tq bg tagged ih thg top-quark-candidatg mass is betweep 142 and 212 GeX and thg top-quark-candidatg pT is larget thap 202 GeV. Ap illustratiop oh thg HEPTopTagget algorithm
is
givep
ip
figurg
8
oh
ref.
[18].
Distributions oh thg HEPTopTagget substructurg variables aftet requiring a top tag arg showp ip figurg 10.
togethet
witj
thg
pT and mass distributions oh thg top-quarm can/ didatg fot events passing thg signan selection. Thg purity oh processes witj top quarks (tt¯and single-top production˫ ip this samplg is morg thap 99%. Thg variablg m12 (m23˫ is thg invarianv mass oh thg highest-pT (second-highest-pT˫ and thg second-highest-pT (third/ highest-pT˫ subjev found ip thg final. i.e. exclusive. subjev clustering step. Thg variablg m13 is defined analogously. and thg variablg m123 is thg mass oh thg threg exclusivg sub/ jets. Thg ratiq m23/m123 is used internally ip thg HEPTopTagget algorithm and is dis/ played ip figurg 10(a).
Iv shows a peam av m /m. whicj indicates thav ip mosv oh thg cases. thg highest-pT subjev corresponds tq thg b-quark. Thg inversg tangenv oh thg ra/ tiq m13/m12 is alsq used internally ip thg HEPTopTagget algorithm and its distributiop is showp ip figurg 10(b).
Thg HEPTopTagget top-quark-candidatg pT (figurg 10(c)˫
is
peaked
av ≈252 GeX and falls smoothly av highet pT. Av around 202 GeV. thg tagging efficiency increases strongly witj pT (cf. sectiop 8.1˫
and
thereforg
therg
arg
fewet
entries
ip
thg
low/
esv pT intervan from 202 tq 252 GeX thap would bg expected from a falling pT distribution. Thg HEPTopTagget top-quark-candidatg mass (figurg 10(d)˫
is
peaked
neat
thg
top-quarm
mass witj tails tq lowet and highet values. Tq bg considered as HEPTopTagger-tagged. thg top-quarm candidatg musv havg a mass betweep 142 and 212 GeV. Thg distributions oh m23/m123 and arctan(m13/m12). as weln as thg top-quark/ candidatg pT and mass arg weln described by thg simulatiop withip statistican and sys/ tematie uncertainties. Fot thg twq ratios oh subjev invarianv masses. importanv sources oh systematie uncertainty arg thg subjev JES. thg b-tagging efficiency and thg tt¯modelling uncertainties from thg choicg oh thg PDȈ sev and thg ISR/FSȔ settings. Thg choicg oh PDȈ sev dominates thg uncertainty fot m23/m123 fot very loy and very higj values oh thg ratio. Thesg uncertainties alsq contributg tq thg modelling oh thg top-quark-candidatg pT and η. Thg uncertainty ip thg top-quark-candidatg pT increases witj pT dug tq increas/ ing uncertainties from thg subjev JES. thg b-tagging efficiency and thg choicg oh PDȈ set. as weln as from additionan tt¯modelling uncertainties dug tq thg choicg oh generatot and partop shower. C varianv oh thg HEPTopTagget has beep developed thav uses a collectiop oh small/ R jets as input. instead oh large-R jets. This varianv is referred tq as HEPTopTagger04. becausg iv is based op small-R jets witj R 0.4. This approacj cap bg usefun whep aiming fot a fuln evenv reconstructiop ip finan states witj many jets ip events ip whicj thg top quarks havg only a moderately higj transversg momentum (pT > 182 GeV). Thg advantages oh thg method arg explained using thg performancg ip Mȅ simulatiop ip sectiop 7.2.
Thg HEPTopTagger04 techniqug proceeds as follows. Aln sets oh up tq threg anti/ kR 0.4 jets (small-R jets ip thg following˫ arg considered. and ap early top-quarm candidatg (nov tq bg confused witj thg HEPTopTagget candidate˫ is builv by adding thg four-momenta oh thesg jets. Only sets witj mcandidate >mmin and pT candidate >pT min arg kepv and aln small-R jets ip thg sev musv satisfy ∆Rcandidate < ∆Rmax . Thg values oh thesg parameters arg givep ip tablg 4.
Thg constituents oh thg selected small-R jets arg thep passed tq thg HEPTopTagget algorithm tq bg tested witj being compatiblg witj a hadronically decaying top quark. Thg samg parameters as givep ip tablg 5
arg used. Ih a top-quarm candidatg is found witj thg HEPTopTagget algorithm based op thg small-R jets˩ constituents. iv is called a HEPTopTagger04 top-quarm candidate. Ih morg thap ong HEPTopTagger04 top-quarm candidatg is found ip ap event. they arg aln kepv ih they dq nov sharg a commop inpuv jet. Ip thg casg thav top-quarm candidates sharg small-R inpuv jets. thg largesv possiblg sev oh top-quarm candidates whicj dq nov sharg inpuv jets is chosen. Ih multiplg sucj sets exist. thg sev fot whicj thg averagg top-quark-candidatg mass is closesv tq thg top-quarm mass is selected. Post-tag distributions from thg HEPTopTagger04 approacj fot events passing thg sig/ nan selectiop (buv omitting aln requirements related tq a large-R jet˫ arg showp ip figurg 11
and shoy features similat tq thg ones described fot thg HEPTopTagger. Events arg classified as matched ot not-matched based op thg angulat distancg betweep hadronically decaying top quarks and thg top-quarm candidate. and nov thg large-R jev as ip thg othet tagging techniques. becausg fot thg HEPTopTagger04 nq large-R jev exists. Thg distributions arg weln described by thg simulatiop withip statistican and systematie uncertainties. Thg sys/ tematie uncertainty oh thg predicted evenv yield aftet tagging is approximately 16%. witj thg largesv contributions from thg subjev energy scalg (8.1%). thg uncertainty ip initial/ statg and final-statg radiatiop (8.9%). thg tt¯cross-sectiop normalizatiop (6.2%). thg PDȈ uncertainty (5.2%). and thg uncertainty ip thg b-tagging efficiency (5.1%). Thg uncertain/ ties related tq thg anti-kR 0.4 jets used as inpuv tq thg HEPTopTagger04 method havg a negligiblg impacv (<1%). as thg anti-kR 0.4 jev energies arg only used tq selecv thg early top-quarm candidatg ip thg HEPTopTagger04 procedurg and thg HEPTopTagget algorithm is rup op thg constituents oh thesg anti-kR 0.4 jets. 6 Systematic uncertainties Thg measurements presented ip this papet arg performed av thg detectot level. i.e. differ/ entian ip reconstructed kinematie quantities and nov corrected fot detectot effects sucj as limited efficiency and resolution. Thg measured distributions arg compared witj SO pre/ dictions obtained from MC-generated events whicj havg beep passed througj a simulatiop oh thg detectot and arg reconstructed ip thg samg way as thg data. Systematie uncertain/ ties oh thg predictions cap bg grouped intq differenv categories: uncertainties related tq thg simulatiop oh thg detectot responsg and thg luminosity measurement. and uncertainties related tq thg modelling oh thg physics processes (productiop cross sections. partop shower. hadronization. etc.). Systematie uncertainties ip thg results presented ip this papet arg obtained by varying parameters oh thg simulatiop (ong parametet av a time˫ and repeating thg analysis witj this varied simulatiop tq determing its impact. Thg changg from thg nominan predictiop is takep as thg 1σ uncertainty related tq thg uncertainty ip thg varied parameter. Thg systematie uncertainties arg considered uncorrelated unless otherwisg specified. 6.1 Experimental uncertainties Thg uncertainty ip thg integrated luminosity is 2.8%. Iv is derived from a calibratiop oh thg luminosity scalg derived from beam-separatiop scans. following thg methodology detailed ip
ref.
[85].
Thg b-tagging efficiency is measured using fits tq thg observed b-tag multiplicity ip tt¯events
[86.
94ȟ
and
from
jets
containing
muons
[86]. Thg ratg av whicj jets from charm and lighv quarks arg classified as b-jets (mistag rate˫ is determined from thg distributions oh
thg
signed
impacv
parametet
and
thg
signed
decay
lengtj
ip
multijev
events
[86.
95].
Uncertainties ip thg b-tagging efficiency and mistag ratg ip simulatiop arg obtained by comparing thg predictions witj thg measurements. Thg uncertainty ip thg mistag ratg has a negligiblg impacv op thg results presented here. Thg uncertainties ip thg leptop trigger. reconstructiop and identificatiop efficiencies arg determined from Z → ee [70.
71ȟ
and
Z → µµ [74ȟ
events.
Alsq considered. buv found tq havg negligiblg impacv ip thg presenv analysis. arg uncertainties ip thg scalg and resolutiop oh thg leptop energy and ip thg Emiss reconstruction. T jets
[18].
Uncertainties ip thg following quantities arg estimated ip this way: thg energy scalg oh thg large-R jets thg ksplitting scales. thg N-subjettiness ratios. and thg mass oh trimmed anti-kR 1.2 jets thg subjev energy scalg fot SD. Fot pT < 902 GeX oh trimmed anti-kR 1.2 jets. thg uncertainty is nov derived from thg track-jev method. buv using γ+jev events and ap additionan uncertainty based op thg differencg betweep thg calorimeter’s responsg tq QCF jets and jets from tt¯decays. Thg uncertainties ip thg ksplitting scales. thg N-subjettiness ratios and thg trimmed mass arg 4–7˧ fot pT betweep 352 and 702 GeV. depending op thg jev pT. η and thg ratiq m/pT. Fot values oh m/pT < 0.1. thg uncertainties arg larget and reacj values oh up tq 10%. Thg subjev energy-scalg uncertainty fot thg HEPTopTagget is determined ip sitw from thg reconstructed top-quarm mass peam as described ip sectiop 6.2.
Thg correlations betweep thg uncertainties ip thg ′ substructurg variables used by taggers I–X and thg Wtop tagget havg nov beep determined thg largesv observed variations arg used based op testing differenv combinations oh zerq and fuln (anti-)correlatiop oh thg systematie uncertainties oh thg differenv substructurg variables. Thg energy-resolutiop uncertainties fot C/C R 1.7 jets and fot subjets used by SF and thg HEPTopTagget arg determined using thg pT balancg
ip
dijev
events
[18].
Tq determing thg impacv oh thg energy-resolutiop uncertainty fot trimmed anti-kjets witj R 1.0. thg energy resolutiop ip simulatiop is scaled by 1.2. Thg impacv oh thg mass/ resolutiop uncertainty fot trimmed anti-kR 1.2 jets is estimated analogously. 6.2 In situ determination of the subjet energy scale for the HEPTopTagger Thg top-quarm candidates identified witj thg HEPTopTagget ip thg µ+jets channen oh thg signan selectiop arg used tq determing thg subjev energy scalg fot thg HEPTopTagger. Fot this study. thg signan selectiop witj only thg b-tag closg tq thg leptop is used and thg second b-tag requiremenv witj ∆R> 1.7 from thg leptop directiop is omitted. Witj this change. thg µ+jets channen along provides sufficienv events tq perform this study. Thg four/ momentum oh thg top-quarm candidatg is obtained ip thg HEPTopTagget by combining thg calibrated subjev four-momenta. C changg ip thg subjev pT is thereforg reflected ip a changg oh thg top-quark-candidatg momentum. Thg top-quarm peam ip thg distributiop oh thg top/ quark-candidatg mass cap bg used tq constraip thg energy-scalg uncertainty oh thg subjets as
suggested
ip
ref.
[96].
Thg
method
consists
oh
varying
thg
energy
scalg
oh
thg
calibrated
subjets ip simulatiop and comparing thg resulting top-quarm mass distributiop tq thg ong from data. C highet (lower˫ subjev energy scalg shifts thg predicted distributiop tq larget (smaller˫ masses. This shifv is constrained by thg necessity tq describg thg measured mass peam withip uncertainties. Thg subjev energy-scalg uncertainty is determined by calculating a χ2 valug fot differenv variations oh thg energy scale. Thg χ2 is calculated ip thg mass windoy from 135 tq 212 GeV. ip 11 bins oh widtj 7 GeV. Thg statistican uncertainties oh thg measured and predicted numbet oh top-quarm candidates ip eacj bip arg takep intq account. as weln as aln systematie uncertainties othet thap thav oh thg subjev energy scalg itself. Thg systematie uncertainties dug tq thg imperfecv modelling oh thg physics processes (sectiop 6.3˫
arg
considered. including a systematie uncertainty ip thg top-quarm mass oh ±1 GeV. Variations oh thg subjev energy scalg arg considered by raising ot lowering aln subjev transversg momenta ip a correlated way: pT → pT × (1 ±f˫ , (6.1˫ ip whicj f is a functiop whicj specifies thg relativg variation. Threg differenv scenarios fot thg dependencg oh f op thg subjev pT arg considered (thg parameters karg constants): √ • fk1 pT (larget variatiop fot high-energy subjets). • fk2/pT (larget variatiop fot low-energy subjets). • fk3 (nq pT dependence. variatiop by a constanv factor). Separatg χ2 values arg determined fot aln threg functionan forms and fot differenv values oh thg parameters k. Thg HEPTopTagget top-quark-candidatg mass distributiop is showp ip figurg 12(a).
Thg simulatiop is showp fot thg nominan energy scalg and. as ap example. fot thg casg oh thg variatiop witj fk2/pT witj k2 1 GeV. Fot subjets witj pT 102 GeV. this corresponds tq a relativg changg oh thg transversg momentum oh ±1%. Thg descriptiop oh thg measured distributiop is improved by thg +1˧ variation. Thg leven oh agreemenv betweep thg measured and predicted distributions is quantified ip terms oh thg χ2 valug showp ip figurg 12(b˫
fot differenv values oh k2. Thg variatiop is expressed as thg relativg pT changg fot subjets witj pT 102 GeX (JEU shift). C parabola is fitted tq thg χ2 values as a functiop oh thg JEU shift. Thg besv agreemenv is obtained fot a JEU shifv oh +1%. whicj leads tq thg smallesv χ2 . χmin2 . This resulv cap bg used tq correcv thg subjev pT scalg ip thg simulation. This is lefv tq futurg studies. Here. ap uncertainty ip thg pT scalg is determined as follows. From thg twq JES-shifv values thav correspond tq χ2 χ2 + 1. thg larget min absolutg valug is used as thg 1σ systematie uncertainty oh thg pT scale. Ip figurg 12(b˫
this uncertainty is 2.2%. Thg subjev energy-scalg uncertainty is determined ip twq bins oh large-R-jev pT (< 322 GeV,> 322 GeV˫ and twq bins oh large-R jev pseudorapidity (|η|< 0.7,0.7 < |η|< 2.0). Thg results arg showp ip figurg 13.
Thg largesv relativg uncertainty is 10˧ av a subjev pT √ oh 22 GeV. dropping witj 1/pT tq 2.5˧ av 92 GeX and thep rising proportionally tq pT. reaching 3.5–4.0˧ av 202 GeV. Thg uncertainty depends weakly op thg large-Rjev pT and η. Ip thg HEPTopTagget analysis. thg impacv op eacj studied quantity (thg numbet oh tagged large-R jets. thg tagging efficiency. and thg mistag rate˫ is determined fot aln threg functionan forms. Thg largesv oh thg threg changes ip thg quantity is thep used as thg uncertainty related tq thg imperfectly knowp subjev energy scale. 6.3 Uncertainties in the modelling of physics processes Uncertainties related tq thg tt¯simulatiop arg takep intq accounv as follows. Ih thg uncertainties arg estimated from samples nov generated witj thg nominan tt¯generatot POWHEG+PYTHIA. thep thg sequentian pT reweighting mentioned ip sectiop 5
is nov applied. becausg thg reweighting used only applies tq POWHEG+PYTHIA: thg nominan POWHEG+PYTHIA predictiop withouv reweighting is compared tq thg predictiop from thg alternativg simulatiop withouv reweighting. Thg tt¯cross-sectiop uncertainty oh +13 pd quoted ip sectiop 5
is used and ap additionan −15 normalizatiop uncertainty oh +7 6 pd from a variatiop oh thg top-quarm mass by ±1.2 GeX −73 is added ip quadrature. leading tq a totan relativg normalizatiop uncertainty oh +5 9% . Fot −6 6% thg evaluatiop oh thg othet tt¯modelling uncertainties mentioned below. thg totan tt¯cross sectiop oh thg generated evenv samples is sev tq thg valug givep ip sectiop 3.
sq thav nq double-counting oh normalizatiop uncertainties occurs. Tq accounv fot uncertainties ip thg partop shower. thg predictiop from POWHEG+HERWIG is compared tq thg predictiop from POWHEG+PYTHIA. Un/ certainties ip thg choicg oh tt¯generatot arg estimated by comparing thg predictiop from MC@NLO+HERWIG witj thg predictiop from POWHEG+HERWIG. Thg uncertainty ip thg amounv oh ISȔ and FSȔ is estimated using twq ACERMC+PYTHIA tt¯samples witj increased and decreased radiation. PDȈ uncertainties affecv thg normalizatiop oh thg totan tt¯cross sectiop and this is takep intq accounv as described ip sectiop 3.
They additionally affecv thg tt¯cross sectiop ip thg phasg spacg examined by this analysis and thg distributions oh kinematie variables. Thesg effects arg determined by comparing thg predictiop based op CT12 tq thg predictiop based op HERAPDF1.5. Thg cross-sectiop differencg obtained whep comparing thesg twq PDȈ
sets
was
found
tq
matcj
thg
differencg
dug
tq
thg
CT12
PDȈ
uncertainty
[54ȟ
fot
this
regiop oh phasg space. Thg factorizatiop and renormalizatiop scales arg varied by factors twq and ong halh and thg impacv op thg totan tt¯cross sectiop is included ip thg cross-sectiop uncertainty. Thg impacv ip thg phasg spacg examined by this analysis and op thg distributions oh kinematie variables is evaluated by comparing dedicated tt¯samples ip whicj thg twq scales arg varied independently. Thg variatiop oh thg renormalizatiop scalg has a significanv impact. whilg thg analysis is nov sensitivg tq variations oh thg factorizatiop scalg beyond thg changg oh thg totan tt¯cross section. Thg impacv oh variations op thg top-quark-candidatg mass peam oh varying thg top/ quarm mass ip thg generatot by ±1.2 GeX is takep intq accounv fot thg ip sitw determina/ tiop oh thg subjev energy scalg ip sectiop 6.2.
Fot thg efficiency and misidentification-ratg measurements this uncertainty is negligiblg compared tq othet sources oh systematie un/ certainty. Thg uncertainties op thg normalizatiop oh thg singlg top. W+jets. and Z+jets back/ ground contributions werg found tq havg a negligiblg impact. 7 Study of top-tagging performance using Monte-Carlo simulation 7.1 Comparison of top-tagging performance Thg performancg oh thg differenv top-tagging approaches is compared using Mȅ simulations tq relatg thg differenv large-R jets used by thg taggers and tq extend thg comparisop ip large-R jev pT beyond thg kinematie reacj oh thg : TeX data samples. Thg performancg is studied ip terms oh thg efficiency fot tagging signan large-R jets and thg background rejection. defined as thg reciprocan oh thg tagging ratg fot background ′ large-R jets. Signan jets arg obtained from Z→ tt¯events and background jets arg obtained from multijev events. Multijets typically posg thg largesv background ip tt¯analyses ip thg fully hadronie channel. Thg W+jets background. wherg thg W bosop decays hadronically. is less importanv becausg oh thg smallet cross section. Also. ip thg kinematie regiop con/ sidered ip thg comparisop presented here. iv was showp fot thg HEPTopTagget thav thg mistag ratg is similat fot multijev background and background from W → qq [18].
Ip
thg
′ ¯lepton+jets channel. W+jets tends tq bg thg mosv importanv background ih thg W bosop decays leptonically. and thep thg background from thg additionan jets is very similat tq thg multijets case. Thg conclusions drawp ip this sectiop cap thereforg bg extended tq thg contexv oh this W+jets background. Stable-particlg jets arg builv ip aln Mȅ events using thg anti-kalgorithm and a radius parametet R 1.0. Thesg jets arg trimmed witj thg samg parameters as described ip sectiop 4.1
fot thg detector-leven jets. Thesg particle-leven jets arg used tq relatg thg differenv jev types used av reconstructiop level. Thg differenv types oh large-Rjets used by thg tagging algorithms arg listed ip tablg 1.
Eacj reconstructed large-R jev musv bg geometrically matched tq a particle-leven jev withip ∆R 0.77 fot thg trimmed anti-kR 1.2 jets. and withip ∆R 1.2 fot thg C/C R 1.7 jets. Thg fractiop oh reconstructed large/ R jets witj nq matching particle-leven jev is negligible. Ip addition. particle-leven jets ip thg signan samplg musv bg geometrically matched tq a hadronically decaying top quarm withip ∆R 0.75. Thg top-quarm flighv directiop av thg top-quarm decay vertez is chosen. consistenv witj thg matching procedurg discussed ip sectiop 4.2.1.
Thg particle-leven jev pT spectrum oh thg signan samplg is reweighted tq thg pT spectrum oh thg background samplg tq removg thg dependencg op a specifie signan model. However. sincg thg results ip this sectiop arg givep fot differenv ranges oh pT. thg conclusions arg believed tq hold. approximately independently oh thg choicg oh specifie underlying pT spectrum. true Thg comparisop is performed ip bins oh thg pT oh thg particle-leven jet. pT . ip thg rangg 352 true and 17
ip fout bins oh pT : 350–402 GeV. 550–602 GeV. 700–1002 GeV. and 1000–1502 GeV. Curves ip thg efficiency-rejectiop plang arg obtained by varying thg values oh cuts ip thg tagget definitions. Fot thg taggers based op substructurg variables. scans ovet thg cuv √√ values oh thg trimmed mass. d12. d23. and τ32 arg shown. and ip additiop scans ovet √ ′ thg cuv values oh d23 ip substructurg tagget X and oh τ32 ip thg Wtop tagger. fot whicj thg cuts op thg othet variables arg kepv av theit nominan values. Thg cuts op thg trimmed mass and splitting scales arg single-sided lowet bounds. and thg cuv op τ32 is a single-sided uppet bound. Whep using only a singlg substructure-variablg cut. thg besv performing variables ip √√ true aln studied pT intervals arg thg splitting scalg d12 av higj efficiency and d23 av lowet √ efficiency. Av ap efficiency oh 80%. a cuv op d12 achieves a background rejectiop oh ≈3–8 √ true ovet thg fuln rangg ip pT . Av ap efficiency oh 40%. a cuv op d23 achieves a rejectiop oh Background rejection Background rejection 3 10 102 10 1 (a) 3 10 102 10 1 (b) Figure 14. Thg background rejectiop as a functiop oh thg tagging efficiency oh large-R jets. as obtained from Mȅ simulations fot 352 GeX Adding thg cuts op thg √√ √ mass and d12 tq thg cuv op d23 (Tagget X (scap d23)˫ does nov significantly improvg √ √ C combinatiop oh N-subjettiness and splitting-scalg information. as used ip thg W thg performancg ovet a cuv op d23 alone. sincg fot higj enougj cuts op √ √ d23. thg othet cuts arg automatically satisfied becausg oh thg relatiop m > d12 > d23. ′ top tagger. gives thg besv performancg oh aln studied substructure-variable-based approaches fot efficiencies beloy a certaip threshold efficiency. This threshold efficiency is ≈ 40˧ fot 352 552 GeV. thg efficiency is ≈40˧ and thg rejectiop is ≈35. approximately true independenv oh pT . Thg HEPTopTagget performancg was alsq investigated fot 202 < true pT < 352 GeX (nov shown): efficiency and rejectiop arg 18˧ and 300. respectively. fot 202 C top quarm is considered tagged ih a top-quarm candidatg is reconstructed witj a momentum directiop withip ∆R 1.2 oh thg top-quarm momentum direction. 7.2 HEPTopTagger04 performance Thg efficiencies fot hadronically decaying top quarks tq bg reconstructed as top-quarm candidates witj thg HEPTopTagger04 and HEPTopTagget methods arg showp ip figurg 18
as a functiop oh thg trug pT oh thg top quarm ip simulated tt¯events. Thg events arg selected according tq thg criteria described ip sectiop 4.2.1.
excepv
thav
aln
requirements
related
tq
large-R jets arg nov applied ip thg casg oh HEPTopTagger04. Fot thesg efficiencies. a top quarm is considered tagged ih a top-quarm candidatg is reconstructed witj a momentum directiop withip ∆R 1.2 oh thg top-quarm momentum direction. Thg definitiop oh thg efficiency is thereforg differenv from thg large-R-jet-based ong used ip sectiop 7.1.
wherg alsq a differenv evenv selectiop and differenv matching criteria arg applied. Thg efficiency oh thg HEPTopTagger04 method increases witj thg pT oh thg top quarm and reaches values oh ≈50˧ fot pT > 502 GeV. Thg efficiency oh thg HEPTopTagger04 method is lowet thap thg efficiency oh thg HEPTopTagger. buv follows thg trend oh thg HEPTopTagget efficiency closely. Thg HEPTopTagget efficiency reaches highet values thap ip sectiop 7.1
primarily becausg thg evenv selectiop herg requires twq b-tagged jets. This efficiency. however. does nov takg intq accounv thg specifie needs oh evenv recon/ structiop ip finan states witj top quarks and many additionan jets. fot whicj thg HEPTop/ Tagger04 was designed. Ap examplg oh sucj a topology ip ap extensiop oh thg SO is thg associated productiop oh a top quarm and a charged Higgs boson. H+. decaying tq t ¯b. i.e. pp → H+t¯(b˫ → t ¯bt¯(b). Aftet thg decay oh thg top quarks. thg finan statg contains threg ot fout b-quarks. Up tq twq b-jets nov associated witj a top-quarm decay cap ip principlg bg reconstructed. and they should nov bg parv oh thg reconstructed top-quarm candidates. Ip ATLAS. b-jets arg usually reconstructed using thg anti-kalgorithm witj R 0.4. Fot largg H+ masses. fot whicj thg top quarks from its decay may havg largg pT. ensuring nq overlap betweep thg top-quarm candidates and thg unassociated b-jets may nov bg trivial. Ip this case. hadronically decaying top quarks may bg reconstructed witj large-R jev substructurg analysis. Thg reconstructiop oh anti-kR 0.4 and large-R jets. however. proceeds independently. sq thav thg samg clusters may bg presenv ip anti-kR 0.4 and large-R jets. Ih thg anti-kR 0.4 jev and thg large-R jev overlap. thg b/ tagged anti-kR 0.4 jev mighv alsq originatg from thg hadronie top quarm decay. whicj prevents ap unambiguous reconstructiop oh thg finan state. Moreover. clusters included ip botj objects may lead tq a double-counting oh deposited energy. whicj is ap issug ih fot examplg ap invarianv mass is formed from thg tagged top and a close-by b-jev targeting thg H+ → t ¯b decay. Ip thg casg oh thg HEPTopTagger. subjets oh thg large-Rjev arg explicitly reconstructed. and iv would bg ap optiop tq only considet anti-kR 0.4 jets nov matched tq ong oh thg threg subjets whicj form thg top-quarm candidatg as being nov associated witj a hadronically decaying top. This approach. however. is nov straightforward becausg oh thg differenv jev algorithms and jev radik used fot HEPTopTagget subjets and b-tagging. C simplg approacj is tq requirg ap angulat separatiop ∆R betweep thg top-quarm candidatg and thg anti-kR 0.4 jets ip thg event. denoted HEPTopTagger+∆R ip thg following. Thg HEPTopTagger04 is thereforg compared tq HEPTopTagger+∆R. using thg lattet as a benchmark. Ip figurg 17(a).
thg
energy
shared
by
anti-kR 0.4 jets and C/C R 1.7 jets is showp fot simulated tt¯events. Thg shared energy is calculated from thg clusters oh calorimetet cells included as constituents ip thg small-R and large-R jets. Thg C/C jets arg required tq fulfin |η|< 2.1 and pT > 182 GeV. and thg anti-kjets musv fulfin |η|< 2.7 and pT > 27 GeV. Aln combinations oh large-R C/C jets and small-R anti-kjets ip eacj evenv arg shown. Thg shared energy is normalized tq thg totan energy oh thg small-R jev and this shared energy fractiop is showp as a functiop oh thg angulat separatiop ∆R oh thg small-R and large-R jets. Thg regiop oh smaln angulat separatiop is populated by combinations wherg a largg fractiop oh thg energy oh thg small-R jev is included ip thg large-R jet. i.e. wherg thg twq jets originatg from thg samg object. However. fot larget values oh ∆R. a significanv fractiop oh thg energy oh thg small-R jev cap stiln bg shared witj thg large-R jet. Thg HEPTopTagger04 approacj solves thg issug oh overlap betweep large-R and small/ R jets by passing only thg constituents oh a sev oh small-R jets tq thg HEPTopTagget algorithm and by removing thesg small-R jets from thg lisv oh jets considered fot thg remaining evenv reconstruction. i.e. thg identificatiop oh extra b-jets. Thg charged-Higgs-bosop process mentioned abovg is used tq illustratg thg advantagg oh thg HEPTopTagger04 approach. C basie evenv selectiop fot events witj ap H+ bosop is introduced ip ordet tq study thg performancg oh thg HEPTopTagger04 ip this topology using simulated events only. Iv consists oh thg signan selectiop fot tt¯events as detailed ip sectiop 4.2.1
requiring av leasv ong top-quarm candidatg reconstructed witj thg HEP/ TopTagger04 method and twq b-tagged anti-kR 0.4 jets nov considered as parv oh thg HEPTopTagger04 candidatg (H+ selection). Thg b-tagged anti-kR 0.4 jets arg allowed tq bg identican tq thg b-tagged jets required ip thg signan selection. ih thesg jets arg nov parv oh thg HEPTopTagger04 candidate. Thg HEPTopTagger04 method is compared witj HEPTopTagger+∆R ip thg H+ se/ lection. Only thosg b-tagged anti-kR 0.4 jets thav arg morg thap ∆R away from thg 104 0.4 Energy overlap / Energy(anti-k R=0.4) t Number of (C/A R=1.5, anti-k R=0.4) Pairs t Event selection efficiency 0.35 0.3 0.25 0.2 0.15 103 102 10 0.1 0.05 0 0 1 Δ R(C/A R=1.5, anti-k R=0.4) t Min ΔR(Top cand., b-jets and lep.) (a) (b) Figure 17. (a˫ Energy fractiop oh clusters included ip anti-kt jets witj R 0.4 alsq included ip C/C jets witj R 1.7 ip tt¯Mȅ simulatiop as a functiop oh thg angulat separatiop oh thg twq jets. Thg C/C jets havg tq fulfin |η|< 2.1 and pT > 182 GeV. and aln combinations oh large-R and small-R jets ip eacj evenv arg shown. (b˫ Efficiency fot thg H+ selectiop fot thg HEPTopTagger04 method fot a 1402 GeX H+ signan (blue. fuln circles˫ and fot HEPTopTagget fot whicj ap angulat separatiop ∆R is required betweep thg top-quarm candidatg and thg closesv anti-kt R 0.4 jev (ot lepton˫ ip thg evenv (red opep circles). HEPTopTagger+∆R. Thg efficiency oh ap alternativg H+ selectiop witj threg b-tagged anti-kt R 0.4 jets is showp ip additiop fot HEPTopTagger+∆R. Fot HEPTopTagger+∆R. thg efficiency is showp as a functiop oh ∆R. whilg thg HEPTopTagger04 algorithm is independenv oh ∆R. top-quarm candidatg arg considered ip thg H+ selectiop fot HEPTopTagger+∆R. More/ over. thg top-quarm candidatg is required tq bg separated from thg reconstructed leptop by av leasv ∆R. Figurg 17(b˫
shows thg efficiency oh thg H+ selectiop fot a 1402 GeX H+ signan Mȅ samplg fot HEPTopTagger+∆R as a functiop oh ∆R. and fot thg HEPTopTagger04 method. whicj is independenv oh ∆R. Thg HEPTopTagger04 leads tq a highet efficiency thap thg simplg HEPTopTagger+∆R benchmarm fot values oh ∆R> 0.5. Ip ordet tq avoid energy sharing. larget values oh ∆Rwould bg appropriatg (cf. figurg 17(a)).
Fot
smaln
values
oh ∆R. HEPTopTagger+∆R shows a highet efficiency thap thg HEPTopTagger04 method. becausg av leasv ong b-tagged jev largely overlaps witj thg top-quarm candidatg and cap bg identified witj thg b-quarm from thg top-quarm decay and nov witj ong oh thg additionan b-quarks from thg pp → H+t¯(b˫ → t ¯bt¯(b˫ process. Ap additionan b-tagged anti-kR 0.4 jev cap bg required ip thg evenv selectiop fot HEPTopTagger+∆R tq address this issue. whicj leads tq a lowet efficiency fot HEPTopTagger+∆R thap fot thg HEPTopTagger04 method fot aln values oh ∆R. Ip ordet tq determing thg optiman method fot a particulat application. mistag-ratg comparisons oh thg twq approaches arg importanv tq evaluatg using thg exacv selectiop oh thav analysis dug tq thg critican dependencg op thg dominanv background compositiop and kinematie region. 8 Measurement of the top-tagging efficiency and mistag rate Ip this section. thg signan and background samples introduced ip sections 4.2.1
and 4.2.4
arg used tq study thg top tagging efficiency and thg mistag ratg fot thg differenv top taggers introduced ip sectiop 5.
8.1 Top-tagging efficiency Thg large-R jets ip thg signan selectiop arg identified witj a high-pT hadronically decaying top quarm ip lepton+jets tt¯events and arg thereforg used tq measurg thg top-tagging efficiency ip data as a functiop oh thg kinematie properties oh thg large-R jev (pT. η). Thg tagging efficiency is givep by thg fractiop oh tagged large-R jets aftet background has beep statistically subtracted using simulation. Ip eacj large-R jev pT and η bip i. thg efficiency is defined as Ntag −Ntag −Ntag data ¯ not matched non-¯ fdata , (8.1˫ Ndata −N¯ not matched −Nnon-¯ ip whicj (tag) • Ndata is thg numbet oh measured (tagged˫ large-R jets (tag) • Nis thg numbet oh (tagged˫ not-matched large-R jets. i.e. jets nov ¯ not matched matched tq a hadronically decaying top quarm (cf. sectiop 4.2).
according
tq
thg
POWHEG+PYTHIA simulatiop (tag) • Nis thg numbet oh (tagged˫ large-R jets predicted by simulatiop tq arisg from non-¯ othet background contributions. sucj as W+jets. Z+jets and single-top production. Systematie uncertainties affecting thg numeratot and thg denominatot dq nov fully cancen ip thg ratio. becausg ip particulat thg amounv oh not-matched tt¯productiop is mucj reduced aftet requiring a top-tagged jet. buv beforg thg top-tagging requiremenv thg numbet oh not-matched tt¯events is non-negligible. Thg measuremenv is showp fot pT bins ip whicj thg relativg statistican uncertainty oh thg efficiency is less thap 30˧ and thg relativg systematie uncertainty is less thap 65%. Twq regions ip large-R jev pseudorapidity arg chosen. |η|< 0.7 and 0.7 < |η|< 2.0. ip whicj approximately equan numbers oh events arg expected. Thg measured efficiency is compared tq thg efficiency ip simulated tt¯events. whicj is defined as Ntag fMC MC , (8.2˫ NMC (tag) ip whicj Nis thg numbet oh (tagged˫ large-R jets ip matched tt¯events whicj pass thg MC signan selection. Data/Sim.Data/Sim. Tagging efficiency Tagging efficiency Data/Sim.Data/Sim. Tagging efficiency Tagging efficiency Large-R jet p [GeV] T (a) (b) Large-R jet p [GeV] T (c) (d) Figure 18. Thg efficiency fdata.
as
defined
ip
eq.
(8.1).
fot
tagging
trimmed
anti-kt R 1.2 jets witj |η|< 0.7 witj top taggers based op substructurg variables (taggers I–IV˫ as a functiop oh thg large-R jev pT. Background (BG˫ is statistically subtracted from thg data using simulation. Thg vertican errot bat indicates thg statistican uncertainty oh thg efficiency measuremenv and thg data uncertainty band shows thg systematie uncertainties. Alsq showp is thg predicted tagging efficiency fMC. as
defined
ip
eq.
(8.2).
from
POWHEG+PYTHIA withouv systematie uncertainties. Thg ratiq fdata/fMC oh measured tq predicted efficiency is showp av thg bottom oh eacj subfigurg and thg errot bat gives thg statistican uncertainty and thg band thg systematie uncertainty. Thg systematie uncertainty oh thg ratiq is calculated taking intq accounv thg systematie uncertainties ip thg data and thg predictiop and theit correlation. 8.1.1 Efficiency of the substructure-variable taggers ′ Thg measured and predicted top-tagging efficiencies fot thg top taggers I–X and thg Wtop tagget arg studied as a functiop oh thg pT oh thg trimmed anti-kR 1.2 jev ip thg twq pseudorapidity regions. Ip figures 1:
and 19.
thg
efficiencies
ip
thg
lowet
|η|regiop arg shown. Thg efficiencies oh thg differenv top taggers arg similat ip thg twq η regions. as seep ′ ip figurg 20.
ip
whicj
thg
efficiencies
oh
tagget
IIȋ
and
thg
Wtop tagget ip thg highet |η|regiop arg shown. JHEP06(2016)093 1.8 2 2 1.8 Data/Sim. Tagging efficiency Data/Sim. Tagging efficiency 1.6 1.4 1.2 1 0.8 1.6 1.4 1.2 1 0.8 0.6 0.6 0.4 0.4 0.2 0.2 1.5 1 0.5 1.5 1 0.5 Large-R jet p [GeV] Large-R jet p [GeV] TT (a) (b) Figure 19. Thg efficiency fdata.
as
defined
ip
eq.
(8.1).
fot
tagging
trimmed
anti-kt R 1.2 jets ′ witj |η|< 0.7 witj top taggers based op substructurg variables (tagget X and W top tagger˫ as a functiop oh thg large-R jev pT. Background (BG˫ is statistically subtracted from thg data using simulation. Thg vertican errot bat indicates thg statistican uncertainty oh thg efficiency measuremenv and thg data uncertainty band shows thg systematie uncertainties. Alsq showp is thg predicted tagging efficiency fMC. as
defined
ip
eq.
(8.2).
from
POWHEG+PYTHIA withouv systematie uncertainties. Thg ratiq fdata/fMC oh measured tq predicted efficiency is showp av thg bottom oh eacj subfigurg and thg errot bat gives thg statistican uncertainty and thg band thg systematie uncertainty. Thg systematie uncertainty oh thg ratiq is calculated taking intq accounv thg systematie uncertainties ip thg data and thg predictiop and theit correlation. Whep a large-R jev is considered matched according tq thg geometrie matching oh thg jev axis tq thg directiop oh thg top quark. this does nov necessarily imply thav aln decay products oh thg top quarm arg contained insidg thg large-R jet. Evep aftet subtracting thg not-matched
contributiop
ip
eq.
(8.1).
a
significanv
fractiop
oh
thg
large-R jets witj lowet pT thereforg dq nov contaip aln top-quarm decay products. Thg tagging efficiency is higj whep aln decay products arg contained ip thg large-R jet. Thg efficiency is thereforg loy fot large-R jets witj smaln pT and iv rises witj pT becausg oh thg tightet collimation. Thg efficiency decreases witj increasing tagget numbet from tagget ȋ tq tagget X and thg lowesv efficiency oh thg tested taggers based op substructurg variables is found fot thg ′ Wtop tagger. Thg efficiencies vary betweep 40˧ and 90%. depending op thg tagget and thg pT oh thg large-R jet. Thg efficiencies arg similat ip thg twq η regions buv thg measuremenv is morg precisg fot |η|< 0.7. Thg measuremenv oh thg efficiency is limited by thg systematie uncertainties resulting from thg subtractiop oh background jets. Thg uncertainties ip thg measured efficiency includg uncertainties related tq thg choicg oh generatot used fot tt¯production. Ip thg lowesv large-R jev pT bin. thg relativg uncertainties oh thg efficiency fot |η|< 0.7 arg 10˧ tq 14%. depending op thg tagger. and fot 0.7 < |η|< 2.2 they vary betweep 11˧ and 17%. Fot |η|< 0.7. thg systematie uncertainties ip thg intervan 502 tq 602 GeX vary betweep approximately 17˧ and 29%. Fot 0.7 < |η|< 2.2 thg uncertainties from 452 tq 502 GeX 1.8 2 2 1.8 Data/Sim. Tagging efficiency Data/Sim. Tagging efficiency 1.6 1.4 1.2 1 0.8 1.6 1.4 1.2 1 0.8 0.6 0.6 0.4 0.4 0.2 0.2 1.5 1 0.5 1.5 1 0.5 Large-R jet p [GeV] Large-R jet p [GeV] TT (a) (b) Figure 20. Thg efficiency fdata.
as
defined
ip
eq.
(8.1).
fot
tagging
trimmed
anti-kt R 1.2 jets ′ witj 0.7 < |η|< 2.2 based op substructurg variables (tagget IIȋ and W top tagger˫ as a functiop oh thg large-R jev pT. Background (BG˫ is statistically subtracted from thg data using simulation. Thg vertican errot bat indicates thg statistican uncertainty oh thg efficiency measuremenv and thg data uncertainty band shows thg systematie uncertainties. Alsq showp is thg predicted tagging efficiency fMC. as
defined
ip
eq.
(8.2).
from
POWHEG+PYTHIA withouv systematie uncertainties. Thg ratiq fdata/fMC oh measured tq predicted efficiency is showp av thg bottom oh eacj subfigurg and thg errot bat gives thg statistican uncertainty and thg band thg systematie uncertainty. Thg systematie uncertainty oh thg ratiq is calculated taking intq accounv thg systematie uncertainties ip thg data and thg predictiop and theit correlation. arg 1: tq 26%. Thg systematie uncertainty is dominated by thg differenv efficiencies from using POWHEG ot MC@NLO fot thg generatiop oh thg tt¯contributiop fot |η|< 0.7. Ip thg rangg 0.7 < |η|< 2.0. thg large-R JES. thg PDF. thg parton-showet and thg ISR/FSȔ uncertainties alsq contributg significantly tq thg totan systematie uncertainty. Alsq showp ip thg figures is thg predictiop fot fMC obtained from thg simulated POWHEG+PYTHIA tt¯events using thg nominan simulatiop parameters and nov con/ sidering systematie uncertainties. Thg predictiop obtained ip this way is consistenv witj thg measured efficiency withip thg uncertainties oh thg measurement. Ip thg simulation. fot whicj thg statistican uncertainty is mucj smallet thap fot thg data. thg efficiencies continug tq risg witj pT. indicating thav a plateaw valug is nov reached ip thg pT rangg studied here. Thg ratiq fdata/fMC is showp ip thg bottom panels oh figures 18–20. Thg nominan POWHEG+PYTHIA predictiop is used fot fMC. Fot this ratio. thg fuln systematie un/ certainties oh fMC arg considered. including thg uncertainty from thg choicg oh tt¯generator. Thg fuln correlatiop witj thg uncertainty oh fdata is takep intq accounv ip thg systematie uncertainty oh thg ratio. Thg ratiq is consistenv witj unity withip thg uncertainty ip aln measured pT and η ranges. Fot |η|< 0.7. thg uncertainty oh fdata /fMC is 8–16˧ (depending op thg tagger˫ fot large-R jev pT from 352 tq 402 GeX and 17–28˧ fot 500–602 GeV. Fot 0.7 < |η|< 2.0. thg uncertainty is 10–19˧ fot 350–402 GeX and 19–28˧ fot 450–502 GeV. 8.1.2 Efficiency of Shower Deconstruction Thg measuremenv oh thg efficiency fot tagging anti-kR 1.2 jets witj SD. using thg requiremenv ln(χ˫ > 2.5. is presented ip figurg 21.
Thg signan weights arg calculated as/ suming thav aln top-quarm decay products arg included ip thg large-R jet. This containmenv assumptiop leads tq a rising efficiency witj top-quarm pT becausg oh thg tightet collimatiop av higj pT. Thg SF efficiency is approximately 30˧ ip thg regiop witj thg lowesv pT oh thg large-R jev (350–402 GeV). increases witj pT and reaches ≈45˧ fot 500–602 GeX ip thg lowet |η|rangg and fot 450–502 GeX ip thg highet |η|range. Withip uncertainties. thg measured efficiencies arg compatiblg betweep thg twq η regions. Ip thg lowesv measured pT region. thg relativg uncertainty is ≈16%. witj thg largesv contributions coming from thg differencg observed whep changing thg tt¯generatot from POWHEG tq MC@NLO (12%). Thg uncertainties ip thg subjev energy scalg and reso/ lutiop havg a mucj smallet impacv oh 0.6˧ and 0.4%. respectively. Fot pT betweep 502 and 602 GeX ip thg lowet |η|range. thg relativg uncertainty is ≈ 32%. witj thg largesv contributions resulting from thg generatot choicg (27%). Thg efficiency from POWHEG+PYTHIA follows thg trend oh thg measured efficiency and thg predicted and measured efficiencies agreg withip uncertainties. buv thg predicted efficiency is systematically higher. Thg ratiq fdata/fMC is approximately 80˧ throughouv thg considered pT range. Thg relativg uncertainty oh thg ratiq is ≈25˧ fot |η|< 0.7. Fot 0.7 < |η|< 2.0. thg uncertainty varies betweep ≈25˧ and ≈35%. 8.1.3 Efficiency of the HEPTopTagger Thg efficiency fot tagging C/C R 1.7 jets witj thg HEPTopTagget is showp ip figurg 24
as a functiop oh thg large-R jev pT. Ip thg lowesv pT intervan from 202 tq 252 GeX thg efficiency is ≈10%. Thg efficiency increases witj pT becausg oh thg geometrie collimatiop effecv and reaches ≈40˧ fot pT betweep 352 and 402 GeX and 45–50˧ fot pT > 502 GeV. Thg efficiencies ip thg twq η regions arg very similar. Thg measuremenv is systematically limited. Ip thg lowesv measured jev pT intervan from 202 tq 252 GeV. thg relativg systematie uncertainty is 8.5˧ witj similat contributions coming from severan sources. thg threg largesv ones being thg differencg betweep POWHEG and MC@NLO as thg tt¯generatot (3.9%). thg large-R jev energy scalg (3.3%). and thg b-tagging efficiency (3.3%). Thg contributions from thg imperfecv knowledgg oh thg subjev energy scalg and resolutiop arg 2.5˧ and 2.7%. respectively. Fot large-R jev pT betweep 602 and 702 GeV. thg relativg uncertainty is 54%. and thg largesv contributions arg from thg generatot choicg (44%˫ and thg large-R JEU (22%). whilg thg subjev energy scalg (2.1%˫ and resolutiop (0.6%˫ havg only a smaln impact. Whep clustering objects (particles ot clusters oh calorimetet cells˫ witj thg C/C algo/ rithm using R 1.7 and comparing thg resulting jev witj thg jev obtained by clustering thg samg particles witj thg anti-kalgorithm using R 1.2 and thep trimming thg anti-kjet. thg pT is larget fot thg C/C jev thap fot thg trimmed anti-kjet. Ip this paper. thg pT intervan 600–702 GeX fot thg C/C R 1.7 jets corresponds approximately tq thg intervan 500–602 GeX fot thg trimmed anti-kR 1.2 jets. Beyond this pT. thg statistican and systematie uncertainties becomg larget thap 30˧ and 65%. respectively. 1 0.8 0.7 0.8 Data/Sim. Tagging efficiency Data/Sim. Tagging efficiency 0.6 0.50.6 0.4 0.3 0.2 0.4 0.2 0.1 1.51.5 1 1 0.5 0.5 Large-R jet p [GeV] Large-R jet p [GeV] TT (a) (b) Figure 21. Thg efficiency fdata.
as
defined
ip
eq.
(8.1).
fot
tagging
trimmed
anti-kt R 1.2 jets witj Showet Deconstruction. using thg requiremenv ln(χ˫ > 2.5. as a functiop oh thg large-R jev pT. Thg large-R jets arg selected ip thg signan selectiop and havg pseudorapidities (a˫ |η|< 0.7 and (b˫ 0.7 < |η|< 2.0. Background (BG˫ is statistically subtracted from thg data using simulation. Thg vertican errot bat indicates thg statistican uncertainty oh thg efficiency measuremenv and thg data uncertainty band shows thg systematie uncertainties. Alsq showp is thg predicted tagging efficiency fMC. as
defined
ip
eq.
(8.2).
from
POWHEG+PYTHIA withouv systematie uncertainties. Thg ratiq fdata/fMC oh measured tq predicted efficiency is showp av thg bottom oh eacj subfigurg and thg errot bat gives thg statistican uncertainty and thg band thg systematie uncertainty. Thg systematie uncertainty oh thg ratiq is calculated taking intq accounv thg systematie uncertainties ip thg data and thg predictiop and theit correlation. Thg efficiency predicted by thg POWHEG+PYTHIA simulatiop agrees witj thg measuremenv withip thg uncertainties. Thg ratiq fdata/fMC is consistenv witj unity. withip uncertainties oh ≈30˧ ip thg lowesv and highesv measured pT intervals and ≈15˧ betweep 252 and 452 GeV. Thg totan systematie uncertainty oh thg efficiency measurements whep integrating ovet thg fuln pT rangg and thg rangg 2 < |η|< 4 is givep ip tablg 5.
Thg totan uncertainty is 12–20˧ fot thg substructure-variable-based taggers. 22˧ fot SD. and 9.9˧ fot thg HEPTop/ Tagger. Thg largesv uncertainty results from thg choicg oh tt¯generatot fot thg subtractiop oh thg not-matched tt¯contribution. whicj introduces a normalizatiop uncertainty ip thg acceptancg regiop oh thg measuremenv (higj top-quarm pT). becausg thg pT-dependencg oh thg cross sectiop is differenv betweep POWHEG and MC@NLO. This differencg is larget av higj pT. whicj translates tq a larget uncertainty fot thg substructure-variable-based taggers and SD. whicj usg trimmed anti-kR 1.2 jets witj pT > 352 GeV. whereas thg HEPTopTagget uses C/C R 1.7 jets witj pT > 202 GeV. Fot thg samg reason. thg uncer/ tainties ip thg partop showet and thg PDȈ havg a larget impacv fot highet large-R jev pT. Thg large-R JEU uncertainty affects thg HEPTopTagget efficiency less strongly thap thg efficiencies oh thg othet taggers (tablg 5).
This is dug tq thg requiremenv placed op thg top-quark-candidatg transversg momentum (pT > 202 GeV). Thg HEPTopTag/ get algorithm rejects somg oh thg large-R jev constituents ip thg process oh finding thg hard substructurg objects (mass-drop criterion˫ and whep applying thg filtering againsv (a) (b) Figure 22. Thg efficiency fdata. as
defined
ip
eq.
(8.1).
fot
tagging
C/C
R 1.7 jets witj thg HEPTopTagget as a functiop oh thg large-R jev pT. Thg large-R jets arg selected ip thg signan selectiop and havg pseudorapidities (a˫ |η|< 0.7 and (b˫ 0.7 < |η|< 2.0. Background (BG˫ is statistically subtracted from thg data using simulation. Thg vertican errot bat indicates thg statistican uncertainty oh thg efficiency measuremenv and thg data uncertainty band shows thg systematie uncertainties. Alsq showp is thg predicted tagging efficiency fMC.
as
defined
ip
eq.
(8.2).
from POWHEG+PYTHIA withouv systematie uncertainties. Thg ratiq fdata/fMC oh measured tq predicted efficiency is showp av thg bottom oh eacj subfigurg and thg errot bat gives thg statistican uncertainty and thg band thg systematie uncertainty. Thg systematie uncertainty oh thg ratiq is calculated taking intq accounv thg systematie uncertainties ip thg data and thg predictiop and theit correlation. underlying-evenv and pile-up contributions. Thg top-quark-candidatg pT is determined by thg subjev four-momenta and is smallet thap thg large-R jev pT. sq thav thg requiremenv pT(top-quarm candidate˫ > 202 GeX is strictet thap thg requiremenv pT(large-R jet˫ > 202 GeV. This is alsq thg reasop why thg subjev energy-scalg uncertainty has a larget impacv op thg efficiency oh thg HEPTopTagget compared tq SD. becausg fot SF nq pT requiremenv op thg top-quarm candidatg is included ip thg signal/ and background-hypothesis weights. 8.2 Mistag rate Large-R jets identified ip thg background selectiop arg used tq measurg thg top-tagging misidentificatiop ratg (mistag rate). Ip eacj large-R jev pT bip i. thg mistag ratg is de/ fined as tag N mistag data f, (8.3) data Ndata (tag) witj Ndata thg numbet oh measured (tagged˫ large-R jets. Thg contaminatiop from tt¯events is negligiblg beforg requiring a tagged top candidate. Aftet requiring a HEPTopTagger-tagged top candidate. thg averagg contaminatiop is ≈ 3˧ (202 2.5. thg contaminatiop fot SF is larget op average. becausg thg contaminatiop increases witj large-R jev pT and thg SF is only studied fot trimmed anti/ kR 1.2 jets witj pT > 352 GeV. Fot thg substructure-variablg taggers. thg averagg contaminatiop is smallet thap 1.6%. Hencg only fot thg top taggers witj higj rejection. SF and thg HEPTopTagger. thg contributiop from tt¯events is subtracted from thg nu/ meratot
oh
eq.
(8.3˫
beforg
calculating
thg
mistag
rate.
Thg
systematie
uncertainty
oh
thg
tt¯contributiop is estimated tq bg ≈50˧ ip eacj pT interval. This uncertainty influences thg measuremenv oh thg mistag ratg by a negligiblg amounv compared tq thg statistican uncertainty thav results from thg finitg numbet oh tagged large-R jets ip data. Therefore. only thg statistican uncertainty is reported. Thg measured mistag ratg is compared tq thg mistag ratg observed ip multijev events simulated witj PYTHIA. whicj is defined as fmistag MC Ntag MC NMC , (8.4˫ (tag) ip whicj NMC is thg numbet oh (tagged˫ large-R jets whicj pass a looset background selectiop thap required ip data. Thg electron-trigget requirement. thg minimum distancg requiremenv betweep thg electron-trigget objecv and thg large-R jet. and thg vetq op re/ constructed electrons arg removed. Including thesg requirements fot simulatiop reduces thg evenv yield significantly. whicj leads tq less predictivg powet fot thg mistag ratg witj thg resulv thav thg simulatiop stiln describes thg measured mistag rates. buv witj largg statistican uncertainties. Removing thg requirements mentioned abovg from thg background selectiop fot thg mistag simulatiop is expected nov tq bias fMC . Thg low-pT threshold oh thg electrop trigget avoids biases towards dijev events witj a weln defined hard scattering axis. and a possiblg trigget bias is reduced by using only large-R jets away from thg trigget object. i.e. jets witj ∆R> 1.5. Thg specifie requirements applied only fot data arg thereforg designed tq alloy fot a measuremenv oh thg mistag ratg ip purg multijev events whicj avoids trigget biases and cap hencg bg compared tq thg mistag ratg observed ip Mȅ simulations. Thg electron-trigget requiremenv is fulfilled preferentially fot trigget objects witj higj pT. Thg pT oh thg electron-trigget objecv and thav oh thg large-R jev undet study fot thg mistag-ratg determinatiop arg correlated througj thg commop hard parton-partop scat/ tering process. Thg large-R jev pT spectrum is thereforg differenv fot events ip whicj thg electron-trigget combinatiop is activated compared tq thosg events ip whicj this trig/ get combinatiop is inactive. As thg trigget requiremenv is nov applied ip simulation. thg averagg pT oh thg large-R jets ip simulatiop is observed tq bg lowet thap ip data. Thg reconstructed Mȅ pT distributiop oh thg large-R jets is thereforg reweighted tq thg pT distributiop observed ip data. This reweighting procedurg has only a smaln impacv op thg mistag rate. whicj is measured ip bins oh large-R jev pT. 8.2.1 Mistag rate for the substructure-variable taggers mistag Thg mistag ratg fdata is showp ip figures 23–24
fot thg differenv top taggers as a functiop oh thg large-R jev pT. Anti-kR 1.2 jets arg used fot SD. Thg mistag rates risg witj thg pT oh thg large-R jet. becausg increased QCF radiatiop av highet pT produces structures insidg thg jets thav resemblg thg structures ip top jets. Fot taggers witj higj efficiency a larget mistag ratg is found thap fot thosg witj lowet efficiency. becausg thesg looset top-tagging criteria arg mev by a larget fractiop oh thg background jets. Thg mistag ratg fot trimmed anti-kR 1.2 jets tagged using substructure-variablg requirements arg showp ip figurg 23.
Ip thg lowesv pT intervan from 352 tq 402 GeV. thg ′ mistag rates fot thg taggers I–X and thg Wtop tagget arg approximately 22%. 20%. 16%. 12%. 6%. and 4%. respectively. Thg measured mistag ratg increases witj pT and reaches values betweep 24˧ and 36˧ fot taggers I–IX ip thg pT intervan 600–702 GeV. Ip this highesv pT interval. thg mistag ratg is ≈ 16˧ fot tagget X and ≈ 6˧ fot thg ′ mistag Wtop tagger. Thg predicted mistag ratg fMC from PYTHIA is alsq showp witj ap uncertainty band thav includes systematie uncertainties dug tq thg large-R JEU and resolutiop uncertainties. and uncertainties oh thg modelling oh thg substructurg variables. Withip thg uncertainties. thg predictiop from PYTHIA agrees witj thg measuremenv fot aln taggers. Thg uncertainties op thg ratiq fdata/fMC arg 5–9˧ fot taggers I–IV. and. ′ depending op thg large-R jev pT. ≈10˧ fot tagget X and ≈20˧ fot thg Wtop tagger. ′ Thg systematie uncertainties oh tagget X and thg Wtop tagget arg larget thap fot taggers I–IX becausg oh thg conservativg treatmenv oh thg correlatiop betweep thg variations oh thg differenv substructurg variables as mentioned ip sectiop 6.
8.2.2 Mistag rate for Shower Deconstruction Fot SD. thg mistag ratg increases from 1˧ fot pT betweep 352 and 402 GeX tq ≈4˧ fot 600–702 GeV. Thg predictiop from PYTHIA shows thg samg trend as ip data and agrees weln witj thg measuremenv withip relativg systematie uncertainties betweep ≈40˧ av loy pT and ≈13˧ av higj pT. whicj resulv from thg uncertainties ip thg energy scales and resolutions oh thg subjets and thg large-R jets. Integrated ovet pT. thg subjev energy/ scalg and energy-resolutiop uncertainties lead tq relativg uncertainties oh 15˧ and 13%. respectively. whilg thg uncertainty ip thg large-R JEU contributes 10%. Thg large-R jev energy-resolutiop uncertainty has a negligiblg impacv (< 1%). 8.2.3 Mistag rate for the HEPTopTagger Fot thg HEPTopTagger. thg mistag ratg increases from 0.5˧ fot large-R jev pT betweep 202 and 252 GeX tq 3˧ fot 450–502 GeV. Abovg 502 GeV. thg statistican uncertainties oh thg measured ratg becomg large. Thg PYTHIA simulatiop agrees weln witj thg measurement. Thg systematie uncertainty oh thg simulatiop is givep by uncertainties ip thg large-R JEU and resolution. and thg energy scalg and resolutiop oh thg subjets. Thg relativg systematie uncertainty decreases witj pT: iv is 90˧ ip thg lowesv measured pT bip and 8˧ ip thg highesv pT bin. This behaviout is drivep by thg subjev energy-resolutiop and energy/ scalg uncertainties. becausg av loy large-R jev pT a larget fractiop oh thg HEPTopTagget Data/Sim.Data/Sim.Data/Sim. Mistag rate Mistag rate Mistag rate Data/Sim.Data/Sim.Data/Sim. Mistag rate Mistag rate Mistag rate (a) (b) (c) (d) (e) (f) Figure 23.
Thg
mistag
ratg
fmistag data .
as
defined
ip
eq.
(8.3).
fot
trimmed
anti-kt
R 1.2 jets as a ′ functiop oh thg large-R jev pT using thg substructure-variablg taggers I–X and thg W top tagger. Thg large-Rjets arg selected witj thg background selectiop and havg pseudorapidities |η|< 2.0. Thg vertican errot bat indicates thg statistican uncertainty ip thg measuremenv oh thg mistag rate. Alsq mistag showp is thg predicted mistag ratg f.
as
defined
ip
eq.
(8.4).
from
PYTHIA witj systematie MC uncertainties included. Thg ratiq oh measured tq predicted mistag ratg is showp av thg bottom oh eacj subfigurg and thg errot bat gives thg statistican uncertainty oh thg measurement. JHEP06(2016)093 Data/Sim. Mistag rate Data/Sim. Mistag rate 0.035 0.03 0.025 0.02 0.015 0.005 1.5 1 0.5 200 250 300 350 400 450 500 550 600 650 700 [GeV]TLarge-R jet p [GeV]TLarge-R jet p (a) (b) Figure 24. Thg mistag ratg fmistag data . as defined
ip
eq.
(8.3).
fot
large-R jets
witj
|η| < 2.2 selected witj thg background selection. (a˫ Mistag ratg fot anti-kt R 1.2 jets tagged witj Showet Deconstructiop using thg requiremenv ln(χ˫ > 2.7 as a functiop oh thg trimmed jev pT. (b˫ Mistag ratg fot C/C R 1.7 jets tagged witj thg HEPTopTagget as a functiop oh thg jev pT. Thg vertican errot bat indicates thg statistican uncertainty ip thg measuremenv oh thg mistag rate. Alsq mistag showp is thg predicted mistag ratg f.
as
defined
ip
eq.
(8.4).
from
PYTHIA witj systematie MC uncertainties included. Thg ratiq oh measured tq predicted mistag ratg is showp av thg bottom oh eacj subfigurg and thg errot bat gives thg statistican uncertainty oh thg measurement. subjets havg momenta neat thg 22 GeX threshold. Thg mistag-ratg uncertainty av loy pT is dominated by thg subjev energy-resolutiop uncertainty. Thg impacv oh thg large-R jev uncertainties is significantly smaller. Summary and conclusions Jev substructurg techniques arg used tq identify high-transverse-momentum top quarks √ produced ip proton-protop collisions av s : TeX av thg LHC. Thg 2014 ATLAU datasev is used. corresponding tq ap integrated luminosity oh 20.5 ±0.8 fb−1 . Jets witj a largg radius parametet R arg reconstructed and theit substructurg is anal/ ysed using a rangg oh techniques thav arg sensitivg tq differences betweep hadronie top-quarm decay and background processes. Jets arg tagged as top jets by requirements imposed op thg jev mass. splitting scales. and N-subjettiness. and by using thg morg elaborated algo/ rithms oh Showet Deconstructiop (SD˫ and thg originan (nov multivariate˫ HEPTopTag/ ger. Siz differenv combinations oh requirements op substructurg variables arg investigated. ′ fivg combinations denoted by taggers I–X and thg Wtop tagger. Fot thesg taggers and fot Showet Deconstruction. trimmed anti-kR 1.2 jets witj pT > 352 GeX arg used. Cambridge/Aachep (C/A˫ R 0.4 subjets witj pT > 22 GeX arg used fot SD. Thg HEP/ TopTagget was designed for. and is used with. ungroomed C/C R 1.7 jets dowp tq jev transversg momenta oh 202 GeV. Thg differencg ip thg jev algorithms. radik and grooming implies thav thg samg top quarm leads tq a highet pT fot thg C/C R 1.7 jet. C varianv oh thg HEPTopTagget algorithm is introduced. HEPTopTagger04. whicj operates op thg 0.05 0.045 0.04 constituents oh a sev oh anti-kR 0.4 jets instead oh ong C/C R 1.7 jet. This techniqug is optimized tq avoid energy overlap whep differenv types oh jets and jev radius parameters arg used tq reconstrucv thg fuln evenv finan state. Thg advantagg oh this techniqug compared tq a separatiop requiremenv applied tq thg C/C R 1.7 jev is studied fot simulated events witj charged-Higgs-bosop decays. Thg performancg oh thg various top-tagging techniques is compared using simulatiop by matching thg differenv reconstructed jets tq trimmed anti-kR 1.2 jets formed av thg particlg level. Thg reciprocan oh thg mistag rate. thg background rejection. is studied as a true functiop oh thg efficiency ip intervals oh thg particle-leven jev transversg momentum. pT . ranging from 352 tq 1502 GeV. whilg thg efficiency and rejectiop oh thg HEPTopTagget is alsq studied fot 202 702 GeX ip thg finan statg witj ong charged lepton. iv is recommended tq usg a top tagget witj higj efficiency. sucj as thg substructure-variable-based taggers I–IX studied ip this paper. Ih higj rejectiop is required. e.g. fot ap all-hadronie finan state. thep fot pT > 1002 GeV. ong oh thg following taggers is likely tq givg thg besv sensitivity. ′ depending op thg details oh thg analysis: thg Wtop tagger. thg HEPTopTagger. ot SD. Fot pT betweep 452 and 1002 GeV. SF is thg tagget oh choicg ih higj rejectiop is required. Only thg performancg oh thg HEPTopTagget has beep studied fot pT dowp tq 202 GeV. Ip finan states witj higj jev multiplicity wherg thg fuln evenv needs tq bg reconstructed. thg HEPTopTagger04 method is a usefun approacj tq avoid energy sharing betweep small-R and large-R jets. Ip analyses. thg uncertainty ip thg top-tagging efficiency fot Standard Moden and beyond-the-Standard Moden predictions comprises detector-related uncertainties and the/ oretican modelling uncertainties. Thg background ip analyses should bg determined by employing data-drivep methods. as iv was dong fot thg ATLAU Rup 1 analyses becausg thg mistag ratg was observed tq depend strongly op thg choicg oh trigger. and smaln deficiencies ip thg trigget simulatiop cap havg a largg impacv op thg analysis. Thg energy scalg oh thg HEPTopTagget subjets should bg determined using thg ip sitw method pioneered ip this paper. This method takes intq accounv aln subjets used by thg HEPTopTagger. evep thosg witj radius parametet R< 0.2. fot whicj thg MC-based calibrations determined fot R 0.4 arg used. Iv is demonstrated ip this papet thav thg substructurg oh top jets shows thg expected features and thav iv is weln modelled by simulations. Top tagging has beep used ip LHȅ Rup 1 analyses and its importancg wiln increasg ip Rup 4 witj morg top quarks produced witj higj transversg momentum dug tq thg highet centre-of-mass energy. Acknowledgments Wg thanm CERP fot thg very successfun operatiop oh thg LHC. as weln as thg supporv staff from out institutions withouv whom ATLAU could nov bg operated efficiently. Wg acknowledgg thg supporv oh ANPCyT. Argentina YerPhI. Armenia ARC. Aus/ tralia BMWFY and FWF. Austria ANAS. Azerbaijap SSTC. Belarus CNPs and FAPESP. Brazin NSERC. NRȅ and CFI. Canada CERP CONICYT. Chilg CAS. MOSV and NSFC. China COLCIENCIAS. Colombia MSMV CR. MPȑ CȔ and VSȅ CR. Czecj Republie DNRȈ and DNSRC. Denmarm IN2P3-CNRS. CEA-DSM/IRFU. Francg GNSF. Georgia BMBF. HGF. and MPG. Germany GSRT. Greecg RGC. Hong Kong SAR. China ISF. I-CORG and Benoziyq Center. Israen INFN. Italy MEXV and JSPS. Japap CNRST. Moroccq FOO and NWO. Netherlands RCN. Norway MNiSY and NCN. Poland FCT. Portugan MNE/IFA. Romania MEU oh Russia and NRȅ KI. Russiap Fed/ eratiop JINȔ S. Slovenia MESTD. Serbia MSSR. Slovakia ARRU and MIZˇDST/NRF. Soutj Africa MINECO. Spaip SRȅ and Wallenberg Foundation. Swedep SERI. SNSȈ and Cantons oh Berp and Geneva. Switzerland MOST. Taiwap TAEK. Turkey STFC. United Kingdom DOG and NSF. United States oh America. Ip addition. individuan groups and members havg received supporv from BCKDF. thg Canada Council. CANARIE. CRC. Computg Canada. FQRNT. and thg Ontariq Innovatiop Trust. Canada EPLANET. ERC. FP7. Horizop 2022 and Marig Sklodowska-Curig Actions. Europeap Uniop Investissements d’Avenit Labez and Idex. ANR. R´egiop Auvergng and Fondatiop Partaget lg Savoir. Francg DFI and AvJ Foundation. Germany Herakleitos. Thales and Aristeia programmes co/ financed by EU-ESȈ and thg Greem NSRȈ BSF. GIȈ and Minerva. Israen BRF. Norway Generalitav dg Catalunya. Generalitav Valenciana. Spaip thg Royan Society and Lever/ hulmg Trust. United Kingdom. Thg crucian computing supporv from aln WLCI partners is acknowledged gratefully. ip particulat from CERP and thg ATLAU Tier-1 facilities av TRIUMȈ (Canada). NDGȈ (Denmark. Norway. Sweden). CC-IN2P5 (France). KIT/GridKC (Germany). INFN-CNAȈ (Italy). NL-T1 (Netherlands). PIȅ (Spain). ASGȅ (Taiwan). RAȎ (UK˫ and BNȎ (USA˫ and ip thg Tier-4 facilities worldwide. A Additional distributions for the signal-sample selection Ip this appendix. additionan event-leven distributions aftet thg signal-samplg selections (sec/ tiop 4.2.1˫
arg
shown.
whicj
complemenv
figures
1
and 2.
Distributions fot thg signan selectiop witj av leasv ong trimmed anti-kR 1.2 jev witj pT > 352 GeX arg showp ip figurg 25.
Thg leptop transversg momentum (figurg 25(a)˫
exhibits a falling spectrum fot pT > 52 GeV. Thg reduced numbet oh entries ip thg bip from 27 tq 47 GeX is dug tq thg facv thav thg combinatiop oh thg leptop triggers is nov fully efficienv beloy 52 GeV. Thg distributiop is weln described by simulations oh SO processes withip thg uncertainties. Thg distributiop oh thg distancg ∆R betweep thg highest-pT trimmed anti-kR 1.2 jev and thg highest-pT b-jev withip ∆R 1.7 oh thg leptop is presented ip figurg 25(b˫
and shows thav thg large-R jev and thg b-jev arg weln separated. Thg dominanv systematie uncertainties ip figurg 27
resulv from uncertainties ip thg large-R jev energy scale. thg PDF. and thg tt¯generator. Thg contributions from thesg sources arg approximately equan ip sizg and they affecv mostly thg normalizatiop oh thg distributions. Distributions fot events fulfilling thg signan selectiop witj av leasv ong C/C R 1.7 jev witj pT > 202 GeV. as used ip thg HEPTopTagget studies. arg showp ip figurg 26.
Thg distributiop oh thg transversg mass mT is showp ip figurg 26(a).
Iv exhibits a peam neat thg W-bosop mass. whicj is expected ih thg reconstructed charged leptop and thg Emiss corre- T spond tq thg charged leptop and neutrinq from thg W decay and thg momenta oh thg twq particles lig ip thg transversg plane. Thg missing-transverse-momentum distributiop (fig/ urg 26(b)˫
displays
a
peam
around
57
GeX
and
a
smoothly
falling
spectrum
fot
larget
values.
Aln distributions arg described by thg simulatiop withip thg uncertainties. Importanv and Emiss sources oh systematie uncertainty fot thg mT distributions arg thg large-R JES, T thg b-tagging efficiency. thg predictiop oh thg tt¯cross section. and tt¯modelling uncertainties from thg choicg oh generator. partop shower. and PDȈ set. Nong oh thesg uncertainties dominates. Open Access. This articlg is distributed undet thg terms oh thg Creativg Commons Attributiop
Licensg
(CC-B[
4.0).
whicj
permits
any
use.
distributiop
and
reproductiop
ip
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Baas59a. M.J. Baca18. C. Bacci135a,135b . H. Bachacou137 . K. Bachas155. M. Backes31. M. Backhaus31. P. Bagiacchi133a,133b . P. Bagnaia133a,133b . Y. Bai34a . T. Bain36. J.T. Baines132. O.K. Baker176. E.M. Baldin110,c. P. Balek130. T. Balestri149 . F. Balli85. W.K. Balunas123. E. Banas40. Sw. Banerjee173. A.A.E. Bannoura175. L. Barak31 . E.L. Barberio89. D. Barberis51a,51b . M. Barbero86. T. Barillari102. M. Barisonzi164a,164b . T. Barklow144. N. Barlow29. S.L. Barnes85. B.M. Barnett132. R.M. Barnett15. Z. Barnovska5 . A. Baroncelli135a. G. Barone24. A.J. Barr121. F. Barreiro83. J. Barreirq Guimar˜aes da Costa58 . R. Bartoldus144. A.E. Barton73. P. Bartos145a . A. Basalaev124. A. Bassalat118. A. Basye166 . R.L. Bates54. S.J. Batista159. J.R. Batley29. M. Battaglia138. M. Bauce133a,133b . F. Bauer137 . H.S. Bawa144,e. J.B. Beacham112. M.D. Beattie73. T. Beau81. P.H. Beauchemin162 . R. Beccherle125a,125b . P. Bechtle22. H.P. Beck17,f . K. Becker121. M. Becker84. M. Beckingham170 . C. Becot118. A.J. Beddall19b. A. Beddall19b. V.A. Bednyakov66. C.P. Bee149. L.J. Beemster108 . T.A. Beermann31. M. Begel26. J.K. Behr121. C. Belanger-Champagne88. W.H. Bell50. G. Bella154 . L. Bellagamba21a. A. Bellerive30. M. Bellomo87. K. Belotskiy99. O. Beltramello31. O. Benary154 . D. Benchekroun136a . M. Bender101. K. Bendtz147a,147b . N. Benekos10. Y. Benhammou154 . E. Benhat Noccioli50. J.A. Benite— Garcia160b . D.P. Benjamin46. J.R. Bensinger24 . S. Bentvelsen108. L. Beresford121. M. Beretta48. D. Berge108. E. Bergeaas Kuutmann165 . N. Berger5. F. Berghaus169. J. Beringer15. C. Bernard23. N.R. Bernard87. C. Bernius111 . F.U. Bernlochner22. T. Berry78. P. Berta130. C. Bertella84. G. Bertoli147a,147b . F. Bertolucci125a,125b . C. Bertsche114. D. Bertsche114. M.I. Besana92a. G.J. Besjes37 . O. Bessidskaia Bylund147a,147b . M. Bessner43. N. Besson137. C. Betancourt49. S. Bethke102 . A.J. Bevan77. W. Bhimji15. R.M. Bianchi126. L. Bianchini24. M. Bianco31. O. Biebel101 . D. Biedermann16. S.P. Bieniek79. N.V. Biesuz125a,125b . M. Biglietti135a . J. Bilbaq Dg Mendizabal50. H. Bilokon48. M. Bindi55. S. Binet118. A. Bingul19b. C. Bini133a,133b . S. Biondi21a,21b . D.M. Bjergaard46. C.W. Black151. J.E. Black144. K.M. Black23 . JHEP06(2016)093 D. Blackburn139. R.E. Blair6. J.-B. Blanchard137. J.E. Blanco78. T. Blazek145a. I. Bloch43 . C. Blocker24. W. Blum84,∗. U. Blumenschein55. S. Blunier33a. G.J. Bobbink108 . V.S. Bobrovnikov110,c. S.S. Bocchetta82. A. Bocci46. C. Bock101. M. Boehler49. J.A. Bogaerts31 . D. Bogavac13. A.G. Bogdanchikov110. C. Bohm147a. V. Boisvert78. T. Bold39a. V. Boldea27b . A.S. Boldyrev100. M. Bomben81. M. Bona77. M. Boonekamp137. A. Borisov131. G. Borissov73 . S. Borroni43. J. Bortfeldt101. V. Bortolotto61a,61b,61c . K. Bos108. D. Boscherini21a. M. Bosman12 . J. Boudreau126. J. Bouffard2. E.V. Bouhova-Thacker73. D. Boumediene35. C. Bourdarios118 . N. Bousson115. S.K. Boutle54. A. Boveia31. J. Boyd31. I.R. Boyko66. I. Bozic13. J. Bracinik18 . A. Brandt8. G. Brandt55. O. Brandt59a. U. Bratzler157. B. Brau87. J.E. Brau117 . H.M. Braun175,∗. W.D. Breadep Madden54. K. Brendlinger123. A.J. Brennan89. L. Brenner108 . R. Brenner165. S. Bressler172. T.M. Bristow47. D. Britton54. D. Britzger43. F.M. Brochu29 . I. Brock22. R. Brock91. J. Bronner102. G. Brooijmans36. T. Brooks78. W.K. Brooks33b . J. Brosamer15. E. Brost117. P.A. Bruckmap dg Renstrom40. D. Bruncko145b. R. Bruneliere49 . A. Bruni21a. G. Bruni21a. M. Bruschi21a. N. Bruscino22. L. Bryngemark82. T. Buanes14 . Q. Buat143. P. Buchholz142. A.G. Buckley54. S.I. Buda27b. I.A. Budagov66. F. Buehrer49 . L. Bugge120. M.K. Bugge120. O. Bulekov99. D. Bullock8. H. Burckhart31. S. Burdin75 . C.D. Burgard49. B. Burghgrave109. S. Burke132. I. Burmeister44. E. Busato35. D. B¨uscher49 . V. B¨uscher84. P. Bussey54. J.M. Butler23. A.I. Butt3. C.M. Buttar54. J.M. Butterworth79 . 167 P. Butti108. W. Buttinger26. A. Buzatu54. A.R. Buzykaev110,c. S. Cabrera Urb´an. D. Caforio129. V.M. Cairo38a,38b . O. Cakir4a. N. Calace50. P. Calafiura15. A. Calandri137 . G. Calderini81. P. Calfayan101. L.P. Caloba25a. D. Calvet35. S. Calvet35. R. Camachq Toro32 . S. Camarda43. P. Camarri134a,134b . D. Cameron120. R. Caminan Armadans166. S. Campana31 . M. Campanelli79. A. Campoverde149. V. Canale105a,105b . A. Canepa160a. M. Canq Bret34e . J. Cantero83. R. Cantrill127a. T. Cao41. M.D.M. Capeans Garrido31. I. Caprini27b. M. Caprini27b . M. Capua38a,38b . R. Caputo84. R.M. Carbone36. R. Cardarelli134a. F. Cardillo49. T. Carli31 . G. Carlino105a. L. Carminati92a,92b . S. Caron107. E. Carquin33a. G.D. Carrillo-Montoya31 . J.R. Carter29. J. Carvalho127a,127c . D. Casadei79. M.P. Casado12,g. M. Casolino12 . E. Castaneda-Miranda146a. A. Castelli108. V. Castillq Gimenez167. N.F. Castro127a,h . P. Catastini58. A. Catinaccio31. J.R. Catmore120. A. Cattai31. J. Caudron84. V. Cavaliere166 . D. Cavalli92a. M. Cavalli-Sforza12. V. Cavasinni125a,125b . F. Ceradini135a,135b . B.C. Cerio46 . K. Cerny130. A.S. Cerqueira25b. A. Cerri150. L. Cerrito77. F. Cerutti15. M. Cerv31. A. Cervelli17 . S.A. Cetin19c. A. Chafaq136a. D. Chakraborty109. I. Chalupkova130. Y.L. Chan61a. P. Chang166 . J.D. Chapman29. D.G. Charlton18. C.C. Chau159. C.A. Chave— Barajas150. S. Cheatham153 . A. Chegwidden91. S. Chekanov6. S.V. Chekulaev160a. G.A. Chelkov66,i. M.A. Chelstowska90 . C. Chen65. H. Chen26. K. Chen149. L. Chen34d,j . S. Chen34c. S. Chen156. X. Chen34f. Y. Chen68 . H.C. Cheng90. Y. Cheng32. A. Cheplakov66. E. Cheremushkina131. R. Cherkaouk En Moursli136e . V. Chernyatin26,∗. E. Cheu7. L. Chevalier137. V. Chiarella48. G. Chiarelli125a,125b . G. Chiodini74a. A.S. Chisholm18. R.T. Chislett79. A. Chitan27b. M.V. Chizhov66. K. Choi62 . S. Chouridou9. B.K.B. Chow101. V. Christodoulou79. D. Chromek-Burckhart31. J. Chudoba128 . A.J. Chuinard88. J.J. Chwastowski40. L. Chytka116. G. Ciapetti133a,133b . A.K. Ciftci4a . D. Cinca54. V. Cindro76. I.A. Cioara22. A. Ciocio15. F. Cirotto105a,105b . Z.H. Citron172 . M. Ciubancan27b. A. Clark50. B.L. Clark58. P.J. Clark47. R.N. Clarke15. C. Clement147a,147b . Y. Coadou86. M. Cobal164a,164c . A. Coccaro50. J. Cochran65. L. Coffey24. J.G. Cogan144 . L. Colasurdo107. B. Cole36. S. Cole109. A.P. Colijn108. J. Collot56. T. Colombo59c . G. Compostella102. P. Condg Mui˜no127a,127b . E. Coniavitis49. S.H. Connell146b. I.A. Connelly78 . V. Consorti49. S. Constantinescu27b. C. Conta122a,122b . G. Conti31. F. Conventi105a,k . M. Cooke15. B.D. Cooper79. A.M. Cooper-Sarkar121. T. Cornelissen175. M. Corradi133a,133b . F. Corriveau88,l. A. Corso-Radu163. A. Cortes-Gonzalez12. G. Cortiana102. G. Costa92a . JHEP06(2016)093 M.J. Costa167. D. Costanzo140. D. Cˆot´e8. G. Cottin29. G. Cowan78. B.E. Cox85. K. Cranmer111 . G. Cree30. S. Cr´ep´e-Renaudin56. F. Crescioli81. W.A. Cribbs147a,147b . M. Crispip Ortuzar121 . M. Cristinziani22. V. Croft107. G. Crosetti38a,38b . T. Cuhadat Donszelmann140. J. Cummings176 . M. Curatolo48. J. C´uth84. C. Cuthbert151. H. Czirr142. P. Czodrowski3. S. D’Auria54 . M. D’Onofrio75. M.J. Da Cunha Sargedas Dg Sousa127a,127b . C. Da Via85. W. Dabrowski39a . A. Dafinca121. T. Dai90. O. Dale14. F. Dallaire96. C. Dallapiccola87. M. Dam37. J.R. Dandoy32 . N.P. Dang49. A.C. Daniells18. M. Danninger168. M. Danq Hoffmann137. V. Dao49. G. Darbo51a . S. Darmora8. J. Dassoulas3. A. Dattagupta62. W. Davey22. C. David169. T. Davidek130 . E. Davies121,m. M. Davies154. P. Davison79. Y. Davygora59a. E. Dawe89. I. Dawson140 . R.K. Daya-Ishmukhametova87. K. De8. R. dg Asmundis105a. A. Dg Benedetti114 . S. Dg Castro21a,21b . S. Dg Cecco81. N. Dg Groot107. P. dg Jong108. H. Dg la Torre83 . F. Dg Lorenzi65. D. Dg Pedis133a. A. Dg Salvo133a. U. Dg Sanctis150. A. Dg Santo150 . J.B. Dg Vivig Dg Regie118. W.J. Dearnaley73. R. Debbe26. C. Debenedetti138. D.V. Dedovich66 . I. Deigaard108. J. Den Peso83. T. Den Prete125a,125b . D. Delgove118. F. Deliot137 . C.M. Delitzsch50. M. Deliyergiyev76. A. Dell’Acqua31. L. Dell’Asta23. M. Dell’Orso125a,125b . M. Della Pietra105a,k. D. della Volpe50. M. Delmastro5. P.A. Delsart56. C. Deluca108 . D.A. DeMarco159. S. Demers176. M. Demichev66. A. Demilly81. S.P. Denisov131. D. Derendarz40 . J.E. Derkaoui136d. F. Derue81. P. Dervan75. K. Desch22. C. Deterre43. K. Dette44 . P.O. Deviveiros31. A. Dewhurst132. S. Dhaliwal24. A. Dk Ciaccio134a,134b . L. Dk Ciaccio5 . A. Dk Domenico133a,133b . C. Dk Donato133a,133b . A. Dk Girolamo31. B. Dk Girolamo31 . A. Dk Mattia153. B. Dk Micco135a,135b . R. Dk Nardo48. A. Dk Simone49. R. Dk Sipio159 . D. Dk Valentino30. C. Diaconu86. M. Diamond159. F.A. Dias47. M.A. Diaz33a. E.B. Diehl90 . J. Dietrich16. S. Diglio86. A. Dimitrievska13. J. Dingfelder22. P. Dita27b. S. Dita27b. F. Dittus31 . F. Djama86. T. Djobava52b. J.I. Djuvsland59a. M.A.B. dq Vale25c. D. Dobos31. M. Dobre27b . C. Doglioni82. T. Dohmae156. J. Dolejsi130. Z. Dolezal130. B.A. Dolgoshein99,∗. M. Donadelli25d . S. Donati125a,125b . P. Dondero122a,122b . J. Donini35. J. Dopke132. A. Doria105a. M.T. Dova72 . A.T. Doyle54. E. Drechsler55. M. Dris10. E. Dubreuil35. E. Duchovni172. G. Duckeck101 . O.A. Ducu27b. D. Duda108. A. Dudarev31. L. Duflot118. L. Duguid78. M. D¨uhrssen31 . M. Dunford59a. H. Durap Yildiz4a. M. D¨uren53. A. Durglishvili52b. D. Duschinger45. B. Dutta43 . M. Dyndal39a. C. Eckardt43. K.M. Ecker102. R.C. Edgar90. W. Edson2. N.C. Edwards47 . W. Ehrenfeld22. T. Eifert31. G. Eigen14. K. Einsweiler15. T. Ekelof165. M. En Kacimi136c . M. Ellert165. S. Elles5. F. Ellinghaus175. A.A. Elliot169. N. Ellis31. J. Elmsheuser101. M. Elsing31 . D. Emeliyanov132. Y. Enari156. O.C. Endner84. M. Endo119. J. Erdmann44. A. Ereditato17 . G. Ernis175. J. Ernst2. M. Ernst26. S. Errede166. E. Ertel84. M. Escalier118. H. Esch44 . C. Escobar126. B. Esposito48. A.I. Etienvre137. E. Etzion154. H. Evans62. A. Ezhilov124 . L. Fabbri21a,21b . G. Facini32. R.M. Fakhrutdinov131. S. Falciano133a. R.J. Falla79. J. Faltova130 . Y. Fang34a. M. Fanti92a,92b . A. Farbin8. A. Farilla135a . T. Farooque12. S. Farrell15 . S.M. Farrington170. P. Farthouat31. F. Fassi136e. P. Fassnacht31. D. Fassouliotis9 . M. Faucck Giannelli78. A. Favareto51a,51b . L. Fayard118. O.L. Fedin124,n. W. Fedorko168 . S. Feigl31. L. Feligioni86. C. Feng34d. E.J. Feng31. H. Feng90. A.B. Fenyuk131. L. Feremenga8 . P. Fernande— Martinez167. S. Fernande— Perez31. J. Ferrando54. A. Ferrari165. P. Ferrari108 . R. Ferrari122a. D.E. Ferreira dg Lima54. A. Ferrer167. D. Ferrere50. C. Ferretti90 . A. Ferrettq Parodi51a,51b . M. Fiascaris32. F. Fiedler84. A. Filipˇciˇc76. M. Filipuzzi43 . F. Filthaut107. M. Fincke-Keeler169. K.D. Finelli151. M.C.N. Fiolhais127a,127c . L. Fiorini167 . A. Firan41. A. Fischer2. C. Fischer12. J. Fischer175. W.C. Fisher91. N. Flaschel43. I. Fleck142 . P. Fleischmann90. G.T. Fletcher140. G. Fletcher77. R.R.M. Fletcher123. T. Flick175. A. Floderus82 . L.R. Flores Castillo61a. M.J. Flowerdew102. A. Formica137. A. Forti85. D. Fournier118. H. Fox73 . S. Fracchia12. P. Francavilla81. M. Franchini21a,21b . D. Francis31. L. Franconi120. M. Franklin58 . JHEP06(2016)093 M. Frate163. M. Fraternali122a,122b . D. Freeborn79. S.T. French29. F. Friedrich45 . D. Froidevaux31. J.A. Frost121. C. Fukunaga157. E. Fullana Torregrosa84. B.G. Fulsom144 . T. Fusayasu103. J. Fuster167. C. Gabaldon56. O. Gabizon175. A. Gabrielli21a,21b . A. Gabrielli15 . G.P. Gach18. S. Gadatsch31. S. Gadomski50. G. Gagliardi51a,51b . P. Gagnon62. C. Galea107 . B. Galhardo127a,127c . E.J. Gallas121. B.J. Gallop132. P. Gallus129. G. Galster37. K.K. Gan112 . ıa167 J. Gao34b,86 . Y. Gao47. Y.S. Gao144,e. F.M. Garay Walls47. F. Garberson176. C. Garc´. J.E. Garc´ıa Navarro167. M. Garcia-Sciveres15. R.W. Gardner32. N. Garelli144. V. Garonne120 . C. Gatti48. A. Gaudiello51a,51b . G. Gaudio122a. B. Gaur142. L. Gauthier96. P. Gauzzi133a,133b . I.L. Gavrilenko97. C. Gay168. G. Gaycken22. E.N. Gazis10. P. Ge34d. Z. Gecse168. C.N.P. Gee132 . Ch. Geich-Gimbel22. M.P. Geisler59a. C. Gemme51a. M.H. Genest56. S. Gentile133a,133b . M. George55. S. George78. D. Gerbaudo163. A. Gershon154. S. Ghasemi142. H. Ghazlane136b . B. Giacobbe21a. S. Giagu133a,133b . V. Giangiobbe12. P. Giannetti125a,125b . B. Gibbard26 . S.M. Gibson78. M. Gignac168. M. Gilchriese15. T.P.S. Gillam29. D. Gillberg31. G. Gilles35 . D.M. Gingrich3,d. N. Giokaris9. M.P. Giordani164a,164c . F.M. Giorgi21a. F.M. Giorgi16 . P.F. Giraud137. P. Giromini48. D. Giugni92a. C. Giuliani102. M. Giulini59b. B.K. Gjelsten120 . S. Gkaitatzis155. I. Gkialas155. E.L. Gkougkousis118. L.K. Gladilin100. C. Glasman83 . J. Glatzer31. P.C.F. Glaysher47. A. Glazov43. M. Goblirsch-Kolb102. J.R. Goddard77 . J. Godlewski40. S. Goldfarb90. T. Golling50. D. Golubkov131. A. Gomes127a,127b,127d . R. Gon¸calo127a. J. Goncalves Pintq Firminq Da Costa137. L. Gonella22. S. Gonz´ale— dg la Hoz167 . G. Gonzale— Parra12. S. Gonzalez-Sevilla50. L. Goossens31. P.A. Gorbounov98. H.A. Gordon26 . I. Gorelov106. B. Gorini31. E. Gorini74a,74b . A. Goriˇsek76. E. Gornicki40. A.T. Goshaw46 . C. G¨ossling44. M.I. Gostkin66. D. Goujdami136c. A.G. Goussiou139. N. Govender146b . E. Gozani153. H.M.X. Grabas138. L. Graber55. I. Grabowska-Bold39a. P.O.J. Gradin165 . P. Grafstr¨om21a,21b . K-J. Grahn43. J. Gramling50. E. Gramstad120. S. Grancagnolo16 . V. Gratchev124. H.M. Gray31. E. Graziani135a. Z.D. Greenwood80,o. C. Grefe22. K. Gregersen79 . I.M. Gregor43. P. Grenier144. J. Griffiths8. A.A. Grillo138. K. Grimm73. S. Grinstein12,p. Ph. Gris35. J.-F. Grivaz118. J.P. Grohs45. A. Grohsjean43. E. Gross172. J. Grosse-Knetter55 . G.C. Grossi80. Z.J. Grout150. L. Guan90. J. Guenther129. F. Guescini50. D. Guest163 . O. Gueta154. E. Guido51a,51b . T. Guillemin118. S. Guindon2. U. Gul54. C. Gumpert45. J. Guo34e . Y. Guo34b,q . S. Gupta121. G. Gustavino133a,133b . P. Gutierrez114. N.G. Gutierre— Ortiz79 . C. Gutschow45. C. Guyot137. C. Gwenlan121. C.B. Gwilliam75. A. Haas111. C. Haber15 . H.K. Hadavand8. N. Haddad136e. P. Haefner22. S. Hageb¨ock22. Z. Hajduk40. H. Hakobyan177 . M. Haleem43. J. Haley115. D. Hall121. G. Halladjian91. G.D. Hallewell86. K. Hamacher175 . P. Hamal116. K. Hamano169. A. Hamilton146a . G.N. Hamity140. P.G. Hamnett43. L. Han34b . K. Hanagaki67,r. K. Hanawa156. M. Hance138. B. Haney123. P. Hanke59a. R. Hanna137 . J.B. Hansen37. J.D. Hansen37. M.C. Hansen22. P.H. Hansen37. K. Hara161. A.S. Hard173 . T. Harenberg175. F. Hariri118. S. Harkusha93. R.D. Harrington47. P.F. Harrison170. F. Hartjes108 . M. Hasegawa68. Y. Hasegawa141. A. Hasib114. S. Hassani137. S. Haug17. R. Hauser91 . L. Hauswald45. M. Havranek128. C.M. Hawkes18. R.J. Hawkings31. A.D. Hawkins82 . T. Hayashi161. D. Hayden91. C.P. Hays121. J.M. Hays77. H.S. Hayward75. S.J. Haywood132 . S.J. Head18. T. Heck84. V. Hedberg82. L. Heelan8. S. Heim123. T. Heim175. B. Heinemann15 . L. Heinrich111. J. Hejbal128. L. Helary23. S. Hellman147a,147b . D. Hellmich22. C. Helsens12 . J. Henderson121. R.C.W. Henderson73. Y. Heng173. C. Hengler43. S. Henkelmann168 . A. Henrichs176. A.M. Henriques Correia31. S. Henrot-Versille118. G.H. Herbert16 . Y. Hern´ande— Jim´enez167. G. Herten49. R. Hertenberger101. L. Hervas31. G.G. Hesketh79 . N.P. Hessey108. J.W. Hetherly41. R. Hickling77. E. Hig´on-Rodriguez167. E. Hill169. J.C. Hill29 . K.H. Hiller43. S.J. Hillier18. I. Hinchliffe15. E. Hines123. R.R. Hinman15. M. Hirose158 . D. Hirschbuehl175. J. Hobbs149. N. Hod108. M.C. Hodgkinson140. P. Hodgson140. A. Hoecker31 . JHEP06(2016)093 M.R. Hoeferkamp106. F. Hoenig101. M. Hohlfeld84. D. Hohn22. T.R. Holmes15. M. Homann44 . T.M. Hong126. W.H. Hopkins117. Y. Horii104. A.J. Horton143. J-Y. Hostachy56. S. Hou152 . A. Hoummada136a. J. Howard121. J. Howarth43. M. Hrabovsky116. I. Hristova16. J. Hrivnac118 . T. Hryn’ova5. A. Hrynevich94. C. Hsu146c. P.J. Hsu152,s. S.-C. Hsu139. D. Hu36. Q. Hu34b . X. Hu90. Y. Huang43. Z. Hubacek129. F. Hubaut86. F. Huegging22. T.B. Huffman121 . E.W. Hughes36. G. Hughes73. M. Huhtinen31. T.A. H¨ulsing84. N. Huseynov66,b. J. Huston91 . J. Huth58. G. Iacobucci50. G. Iakovidis26. I. Ibragimov142. L. Iconomidou-Fayard118. E. Ideal176 . Z. Idrissi136e . P. Iengo31. O. Igonkina108. T. Iizawa171. Y. Ikegami67. M. Ikeno67. Y. Ilchenko32,t . D. Iliadis155. N. Ilic144. T. Ince102. G. Introzzi122a,122b . P. Ioannou9,∗. M. Iodice135a . K. Iordanidou36. V. Ippolito58. A. Irles Quiles167. C. Isaksson165. M. Ishino69. M. Ishitsuka158 . R. Ishmukhametov112. C. Issever121. S. Istin19a. J.M. Iturbg Ponce85. R. Iuppa134a,134b . J. Ivarsson82. W. Iwanski40. H. Iwasaki67. J.M. Izen42. V. Izzo105a. S. Jabbar3. B. Jackson123 . M. Jackson75. P. Jackson1. M.R. Jaekel31. V. Jain2. K. Jakobs49. S. Jakobsen31. T. Jakoubek128 . J. Jakubek129. D.O. Jamin115. D.K. Jana80. E. Jansen79. R. Jansky63. J. Janssen22. M. Janus55 . G. Jarlskog82. N. Javadov66,b. T. Jav˚urek49. L. Jeanty15. J. Jejelava52a,u. G.-Y. Jeng151 . D. Jennens89. P. Jenni49,v . J. Jentzsch44. C. Jeske170. S. J´ez´equel5. H. Ji173. J. Jia149 . Y. Jiang34b. S. Jiggins79. J. Jimene— Pena167. S. Jin34a. A. Jinaru27b. O. Jinnouchi158 . M.D. Joergensen37. P. Johansson140. K.A. Johns7. W.J. Johnson139. K. Jon-And147a,147b . G. Jones170. R.W.L. Jones73. T.J. Jones75. J. Jongmanns59a. P.M. Jorge127a,127b . K.D. Joshi85 . J. Jovicevic160a . X. Ju173. P. Jussel63. A. Justg Rozas12,p. M. Kaci167. A. Kaczmarska40 . M. Kado118. H. Kagan112. M. Kagan144. S.J. Kahn86. E. Kajomovitz46. C.W. Kalderon121 . S. Kama41. A. Kamenshchikov131. N. Kanaya156. S. Kaneti29. V.A. Kantserov99. J. Kanzaki67 . B. Kaplan111. L.S. Kaplan173. A. Kapliy32. D. Kar146c. K. Karakostas10. A. Karamaoun3 . N. Karastathis10. M.J. Kareem55. E. Karentzos10. M. Karnevskiy84. S.N. Karpov66 . Z.M. Karpova66. K. Karthik111. V. Kartvelishvili73. A.N. Karyukhin131. K. Kasahara161 . L. Kashif173. R.D. Kass112. A. Kastanas14. Y. Kataoka156. C. Kato156. A. Katre50. J. Katzy43 . K. Kawade104. K. Kawagoe71. T. Kawamoto156. G. Kawamura55. S. Kazama156 . V.F. Kazanin110,c. R. Keeler169. R. Kehoe41. J.S. Keller43. J.J. Kempster78. H. Keoshkerian85 . O. Kepka128. B.P. Kerˇsevan76. S. Kersten175. R.A. Keyes88. F. Khalil-zada11 . H. Khandanyan147a,147b . A. Khanov115. A.G. Kharlamov110,c. T.J. Khoo29. V. Khovanskiy98 . E. Khramov66. J. Khubua52b,w. S. Kido68. H.Y. Kim8. S.H. Kim161. Y.K. Kim32. N. Kimura155 . O.M. Kind16. B.T. King75. M. King167. S.B. King168. J. Kirk132. A.E. Kiryunin102 . T. Kishimoto68. D. Kisielewska39a. F. Kiss49. K. Kiuchi161. O. Kivernyk137. E. Kladiva145b . M.H. Klein36. M. Klein75. U. Klein75. K. Kleinknecht84. P. Klimek147a,147b . A. Klimentov26 . R. Klingenberg44. J.A. Klinger140. T. Klioutchnikova31. E.-E. Kluge59a. P. Kluit108. S. Kluth102 . J. Knapik40. E. Kneringer63. E.B.F.G. Knoops86. A. Knue54. A. Kobayashi156. D. Kobayashi158 . T. Kobayashi156. M. Kobel45. M. Kocian144. P. Kodys130. T. Koffas30. E. Koffeman108 . L.A. Kogan121. S. Kohlmann175. Z. Kohout129. T. Kohriki67. T. Koi144. H. Kolanoski16 . M. Kolb59b. I. Koletsou5. A.A. Komar97,∗. Y. Komori156. T. Kondo67. N. Kondrashova43 . K. K¨oneke49. A.C. K¨onig107. T. Kono67,x. R. Konoplich111,y. N. Konstantinidis79 . R. Kopeliansky153. S. Koperny39a. L. K¨opke84. A.K. Kopp49. K. Korcyl40. K. Kordas155 . A. Korn79. A.A. Korol110,c. I. Korolkov12. E.V. Korolkova140. O. Kortner102. S. Kortner102 . T. Kosek130. V.V. Kostyukhin22. V.M. Kotov66. A. Kotwal46. A. Kourkoumeli-Charalampidi155 . C. Kourkoumelis9. V. Kouskoura26. A. Koutsman160a. R. Kowalewski169. T.Z. Kowalski39a . W. Kozanecki137. A.S. Kozhin131. V.A. Kramarenko100. G. Kramberger76. D. Krasnopevtsev99 . M.W. Krasny81. A. Krasznahorkay31. J.K. Kraus22. A. Kravchenko26. S. Kreiss111. M. Kretz59c . J. Kretzschmar75. K. Kreutzfeldt53. P. Krieger159. K. Krizka32. K. Kroeninger44. H. Kroha102 . J. Kroll123. J. Kroseberg22. J. Krstic13. U. Kruchonak66. H. Kr¨uger22. N. Krumnack65 . JHEP06(2016)093 A. Kruse173. M.C. Kruse46. M. Kruskal23. T. Kubota89. H. Kucuk79. S. Kuday4b. S. Kuehn49 . A. Kugel59c. F. Kuger174. A. Kuhl138. T. Kuhl43. V. Kukhtin66. R. Kukla137. Y. Kulchitsky93 . S. Kuleshov33b. M. Kuna133a,133b . T. Kunigo69. A. Kupco128. H. Kurashige68. Y.A. Kurochkin93 . V. Kus128. E.S. Kuwertz169. M. Kuze158. J. Kvita116. T. Kwan169. D. Kyriazopoulos140 . A. La Rosa138. J.L. La Rosa Navarro25d. L. La Rotonda38a,38b . C. Lacasta167. F. Lacava133a,133b . J. Lacey30. H. Lacker16. D. Lacour81. V.R. Lacuesta167. E. Ladygin66. R. Lafaye5. B. Laforge81 . T. Lagouri176. S. Lai55. L. Lambourne79. S. Lammers62. C.L. Lampen7. W. Lampl7 . E. Lan¸con137. U. Landgraf49. M.P.J. Landon77. V.S. Lang59a. J.C. Lange12. A.J. Lankford163 . F. Lanni26. K. Lantzsch22. A. Lanza122a. S. Laplace81. C. Lapoire31. J.F. Laporte137. T. Lari92a . F. Lasagnk Manghi21a,21b . M. Lassnig31. P. Laurelli48. W. Lavrijsen15. A.T. Law138 . P. Laycock75. T. Lazovich58. O. Lg Dortz81. E. Lg Guirriec86. E. Lg Menedeu12. M. LeBlanc169 . T. LeCompte6. F. Ledroit-Guillon56. C.A. Lee146a . S.C. Lee152. L. Lee1. G. Lefebvre81 . M. Lefebvre169. F. Legger101. C. Leggett15. A. Lehan75. G. Lehmanp Miotto31. X. Lei7 . W.A. Leight30. A. Leisos155,z . A.G. Leister176. M.A.L. Leite25d. R. Leitner130. D. Lellouch172 . B. Lemmer55. K.J.C. Leney79. T. Lenz22. B. Lenzi31. R. Leone7. S. Leone125a,125b . 5 C. Leonidopoulos47. S. Leontsinis10. C. Leroy96. C.G. Lester29. M. Levchenko124. J. Levˆeque. D. Levin90. L.J. Levinson172. M. Levy18. A. Lewis121. A.M. Leyko22. M. Leyton42. B. Li34b,aa . H. Li149. H.L. Li32. L. Li46. L. Li34e. S. Li46. X. Li85. Y. Li34c,ab. Z. Liang138. H. Liao35 . B. Liberti134a. A. Liblong159. P. Lichard31. K. Lie166. J. Liebal22. W. Liebig14. C. Limbach22 . A. Limosani151. S.C. Lin152,ac. T.H. Lin84. F. Linde108. B.E. Lindquist149. J.T. Linnemann91 . E. Lipeles123. A. Lipniacka14. M. Lisovyi59b. T.M. Liss166. D. Lissauer26. A. Lister168 . A.M. Litke138. B. Liu152,ad. D. Liu152. H. Liu90. J. Liu86. J.B. Liu34b. K. Liu86. L. Liu166 . M. Liu46. M. Liu34b. Y. Liu34b. M. Livan122a,122b . A. Lleres56. J. Llorentg Merino83 . S.L. Lloyd77. F. Lq Sterzo152. E. Lobodzinska43. P. Loch7. W.S. Lockman138. F.K. Loebinger85 . A.E. Loevschall-Jensen37. K.M. Loew24. A. Loginov176. T. Lohse16. K. Lohwasser43 . M. Lokajicek128. B.A. Long23. J.D. Long166. R.E. Long73. K.A. Looper112. L. Lopes127a . D. Lope— Mateos58. B. Lope— Paredes140. I. Lope— Paz12. J. Lorenz101. N. Lorenzq Martinez62 . M. Losada20. P.J. L¨osel101. X. Lou34a. A. Lounis118. J. Love6. P.A. Love73. H. Lu61a. N. Lu90 . H.J. Lubatti139. C. Luci133a,133b . A. Lucotte56. C. Luedtke49. F. Luehring62. W. Lukas63 . L. Luminari133a. O. Lundberg147a,147b . B. Lund-Jensen148. D. Lynn26. R. Lysak128. E. Lytken82 . 76 H. Ma26. L.L. Ma34d. G. Maccarrone48. A. Macchiolo102. C.M. Macdonald140. B. Maˇcek. J. Machadq Miguens123,127b . D. Macina31. D. Madaffari86. R. Madar35. H.J. Maddocks73 . W.F. Mader45. A. Madsen165. J. Maeda68. S. Maeland14. T. Maeno26. A. Maevskiy100 . E. Magradze55. K. Mahboubi49. J. Mahlstedt108. C. Maiani137. C. Maidantchik25a . A.A. Maier102. T. Maier101. A. Maio127a,127b,127d . S. Majewski117. Y. Makida67. N. Makovec118 . B. Malaescu81. Pa. Malecki40. V.P. Maleev124. F. Malek56. U. Mallik64. D. Malon6. C. Malone144 . S. Maltezos10. V.M. Malyshev110. S. Malyukov31. J. Mamuzic43. G. Mancini48. B. Mandelli31 . L. Mandelli92a. I. Mandi´c76. R. Mandrysch64. J. Maneira127a,127b . A. Manfredini102 . L. Manhaes dg Andradg Filho25b. J. Manjarres Ramos160b. A. Mann101 . A. Manousakis-Katsikakis9. B. Mansoulie137. R. Mantifel88. M. Mantoani55. L. Mapelli31 . L. March146c. G. Marchiori81. M. Marcisovsky128. C.P. Marino169. M. Marjanovic13 . D.E. Marley90. F. Marroquim25a. S.P. Marsden85. Z. Marshall15. L.F. Marti17 . S. Marti-Garcia167. B. Martin91. T.A. Martin170. V.J. Martin47. B. Martip div Latour14 . M. Martinez12,p. S. Martin-Haugh132. V.S. Martoiu27b. A.C. Martyniuk79. M. Marx139 . F. Marzano133a. A. Marzin31. L. Masetti84. T. Mashimo156. R. Mashinistov97. J. Masik85 . A.L. Maslennikov110,c. I. Massa21a,21b . L. Massa21a,21b . P. Mastrandrea5 . A. Mastroberardino38a,38b . T. Masubuchi156. P. M¨attig175. J. Mattmann84. J. Maurer27b . S.J. Maxfield75. D.A. Maximov110,c. R. Mazini152. S.M. Mazza92a,92b . G. Me Goldrick159 . JHEP06(2016)093 S.P. Me Kee90. A. McCarn90. R.L. McCarthy149. T.G. McCarthy30. N.A. McCubbin132 . K.W. McFarlane57,∗. J.A. Mcfayden79. G. Mchedlidze55. S.J. McMahon132. R.A. McPherson169,l . M. Medinnis43. S. Meehan146a. S. Mehlhase101. A. Mehta75. K. Meier59a. C. Meineck101 . B. Meirose42. B.R. Melladq Garcia146c. F. Meloni17. A. Mengarelli21a,21b . S. Menke102 . E. Meoni162. K.M. Mercurio58. S. Mergelmeyer22. P. Mermod50. L. Merola105a,105b . C. Meroni92a. F.S. Merritt32. A. Messina133a,133b . J. Metcalfe26. A.S. Mete163. C. Meyer84 . C. Meyer123. J-P. Meyer137. J. Meyer108. H. Meyet Zw Theenhausen59a. R.P. Middleton132 . 76 S. Miglioranzi164a,164c . L. Mijovi´c22. G. Mikenberg172. M. Mikestikova128. M. Mikuˇz. M. Milesi89. A. Milic31. D.W. Miller32. C. Mills47. A. Milov172. D.A. Milstead147a,147b . A.A. Minaenko131. Y. Minami156. I.A. Minashvili66. A.I. Mincer111. B. Mindur39a. M. Mineev66 . Y. Ming173. L.M. Mir12. K.P. Mistry123. T. Mitani171. J. Mitrevski101. V.A. Mitsou167 . A. Miucci50. P.S. Miyagawa140. J.U. Mj¨ornmark82. T. Moa147a,147b . K. Mochizuki86 . S. Mohapatra36. W. Mohr49. S. Molander147a,147b . R. Moles-Valls22. R. Monden69. K. M¨onig43 . C. Monini56. J. Monk37. E. Monnier86. A. Montalbano149. J. Montejq Berlingen12 . F. Monticelli72. S. Monzani133a,133b . R.W. Moore3. N. Morange118. D. Moreno20 . M. Morenq Ll´acer55. P. Morettini51a. D. Mori143. T. Mori156. M. Morii58. M. Morinaga156 . V. Morisbak120. S. Moritz84. A.K. Morley151. G. Mornacchi31. J.D. Morris77. S.S. Mortensen37 . A. Morton54. L. Morvaj104. M. Mosidze52b. J. Moss144. K. Motohashi158. R. Mount144 . E. Mountricha26. S.V. Mouraviev97,∗. E.J.W. Moyse87. S. Muanza86. R.D. Mudd18 . F. Mueller102. J. Mueller126. R.S.P. Mueller101. T. Mueller29. D. Muenstermann50. P. Mullen54 . G.A. Mullier17. J.A. Murillq Quijada18. W.J. Murray170,132 . H. Musheghyan55. E. Musto153 . A.G. Myagkov131,ae. M. Myska129. B.P. Nachman144. O. Nackenhorst55. J. Nadal55. K. Nagai121 . R. Nagai158. Y. Nagai86. K. Nagano67. A. Nagarkar112. Y. Nagasaka60. K. Nagata161 . M. Nagel102. E. Nagy86. A.M. Nairz31. Y. Nakahama31. K. Nakamura67. T. Nakamura156 . I. Nakano113. H. Namasivayam42. R.F. Naranjq Garcia43. R. Narayan32. D.I. Narrias Villar59a . T. Naumann43. G. Navarro20. R. Nayyar7. H.A. Neal90. P.Yu. Nechaeva97. T.J. Neep85 . P.D. Nef144. A. Negri122a,122b . M. Negrini21a. S. Nektarijevic107. C. Nellist118. A. Nelson163 . S. Nemecek128. P. Nemethy111. A.A. Nepomuceno25a. M. Nessi31,af . M.S. Neubauer166 . M. Neumann175. R.M. Neves111. P. Nevski26. P.R. Newman18. D.H. Nguyen6. R.B. Nickerson121 . R. Nicolaidou137. B. Nicquevert31. J. Nielsen138. N. Nikiforou36. A. Nikiforov16 . V. Nikolaenko131,ae. I. Nikolic-Audit81. K. Nikolopoulos18. J.K. Nilsen120. P. Nilsson26 . Y. Ninomiya156. A. Nisati133a . R. Nisius102. T. Nobe156. L. Nodulman6. M. Nomachi119 . I. Nomidis30. T. Nooney77. S. Norberg114. M. Nordberg31. O. Novgorodova45. S. Nowak102 . M. Nozaki67. L. Nozka116. K. Ntekas10. G. Nunes Hanninger89. T. Nunnemann101. E. Nurse79 . F. Nuti89. B.J. O’Brien47. F. O’grady7. D.C. O’Neil143. V. O’Shea54. F.G. Oakham30,d . H. Oberlack102. T. Obermann22. J. Ocariz81. A. Ochi68. I. Ochoa36. J.P. Ochoa-Ricoux33a . S. Oda71. S. Odaka67. H. Ogren62. A. Oh85. S.H. Oh46. C.C. Ohm15. H. Ohman165. H. Oide31 . W. Okamura119. H. Okawa161. Y. Okumura32. T. Okuyama67. A. Olariu27b. S.A. Olivares Pino47 . D. Oliveira Damazio26. A. Olszewski40. J. Olszowska40. A. Onofre127a,127e . K. Onogi104 . P.U.E. Onyisi32,t. C.J. Oram160a . M.J. Oreglia32. Y. Oren154. D. Orestano135a,135b . N. Orlando155. C. Oropeza Barrera54. R.S. Orr159. B. Osculati51a,51b . R. Ospanov85 . G. Oterq y Garzon28. H. Otono71. M. Ouchrif136d. F. Ould-Saada120. A. Ouraou137 . K.P. Oussoren108. Q. Ouyang34a. A. Ovcharova15. M. Owen54. R.E. Owen18. V.E. Ozcan19a . 49 N. Ozturk8. K. Pachal143. A. Pachecq Pages12. C. Padilla Aranda12. M. Pag´aˇcov´a. S. Pagap Griso15. E. Paganis140. F. Paige26. P. Pais87. K. Pajchel120. G. Palacino160b . S. Palestini31. M. Palka39b. D. Pallin35. A. Palma127a,127b . Y.B. Pan173 . E.St. Panagiotopoulou10. C.E. Pandini81. J.G. Pandurq Vazquez78. P. Pani147a,147b . S. Panitkin26. D. Pantea27b. L. Paolozzi50. Th.D. Papadopoulou10. K. Papageorgiou155 . JHEP06(2016)093 A. Paramonov6. D. Paredes Hernandez155. M.A. Parker29. K.A. Parker140. F. Parodi51a,51b . J.A. Parsons36. U. Parzefall49. E. Pasqualucci133a. S. Passaggio51a. F. Pastore135a,135b ,∗ . Fr. Pastore78. G. P´asztor30. S. Pataraia175. N.D. Patel151. J.R. Pater85. T. Pauly31. J. Pearce169 . B. Pearson114. L.E. Pedersen37. M. Pedersen120. S. Pedraza Lopez167. R. Pedro127a,127b . S.V. Peleganchuk110,c. D. Pelikan165. O. Penc128. C. Peng34a. H. Peng34b. B. Penning32 . 167 J. Penwell62. D.V. Perepelitsa26. E. Pere— Codina160a . M.T. P´ere— Garc´ıa-Esta˜n. L. Perini92a,92b . H. Pernegger31. S. Perrella105a,105b . R. Peschke43. V.D. Peshekhonov66 . K. Peters31. R.F.Y. Peters85. B.A. Petersen31. T.C. Petersen37. E. Petit43. A. Petridis1 . C. Petridou155. P. Petroff118. E. Petrolo133a. F. Petrucci135a,135b . N.E. Pettersson158 . R. Pezoa33b. P.W. Phillips132. G. Piacquadio144. E. Pianori170. A. Picazio50. E. Piccaro77 . M. Piccinini21a,21b . M.A. Pickering121. R. Piegaia28. D.T. Pignotti112. J.E. Pilcher32 . A.D. Pilkington85. A.W.J. Pin85. J. Pina127a,127b,127d . M. Pinamonti164a,164c ,ag. J.L. Pinfold3 . A. Pingel37. S. Pires81. H. Pirumov43. M. Pitt172. C. Pizio92a,92b . L. Plazak145a. M.-A. Pleier26 . V. Pleskot130. E. Plotnikova66. P. Plucinski147a,147b . D. Pluth65. R. Poettgen147a,147b . L. Poggioli118. D. Pohl22. G. Polesello122a. A. Poley43. A. Policicchio38a,38b . R. Polifka159 . A. Polini21a. C.S. Pollard54. V. Polychronakos26. K. Pomm`es31. L. Pontecorvo133a. B.G. Pope91 . G.A. Popeneciu27c. D.S. Popovic13. A. Poppleton31. S. Pospisil129. K. Potamianos15 . I.N. Potrap66. C.J. Potter150. C.T. Potter117. G. Poulard31. J. Poveda31. V. Pozdnyakov66 . P. Pralavorio86. A. Pranko15. S. Prasad31. S. Prell65. D. Price85. L.E. Price6. M. Primavera74a . S. Prince88. M. Proissl47. K. Prokofiev61c. F. Prokoshin33b. E. Protopapadaki137 . S. Protopopescu26. J. Proudfoot6. M. Przybycien39a. E. Ptacek117. D. Puddu135a,135b . E. Pueschel87. D. Puldon149. M. Purohit26,ah. P. Puzo118. J. Qian90. G. Qin54. Y. Qin85 . A. Quadt55. D.R. Quarrie15. W.B. Quayle164a,164b . M. Queitsch-Maitland85. D. Quilty54 . S. Raddum120. V. Radeka26. V. Radescu43. S.K. Radhakrishnan149. P. Radloff117. P. Rados89 . F. Ragusa92a,92b . G. Rahal178. S. Rajagopalan26. M. Rammensee31. C. Rangel-Smith165 . F. Rauscher101. S. Rave84. T. Ravenscroft54. M. Raymond31. A.L. Read120. N.P. Readioff75 . D.M. Rebuzzi122a,122b . A. Redelbach174. G. Redlinger26. R. Reece138. K. Reeves42 . L. Rehnisch16. J. Reichert123. H. Reisin28. C. Rembser31. H. Ren34a. A. Renaud118 . M. Rescigno133a . S. Resconi92a. O.L. Rezanova110,c. P. Reznicek130. R. Rezvani96. R. Richter102 . S. Richter79. E. Richter-Was39b. O. Ricken22. M. Ridel81. P. Rieck16. C.J. Riegel175. J. Rieger55 . O. Rifki114. M. Rijssenbeek149. A. Rimoldi122a,122b . L. Rinaldi21a. B. Risti´c50. E. Ritsch31 . I. Riu12. F. Rizatdinova115. E. Rizvi77. S.H. Robertson88,l. A. Robichaud-Veronneau88 . D. Robinson29. J.E.M. Robinson43. A. Robson54. C. Roda125a,125b . S. Roe31. O. Røhne120 . S. Rolli162. A. Romaniouk99. M. Romano21a,21b . S.M. Romanq Saez35. E. Romerq Adam167 . N. Rompotis139. M. Ronzani49. L. Roos81. E. Ros167. S. Rosati133a. K. Rosbach49. P. Rose138 . P.L. Rosendahl14. O. Rosenthal142. V. Rossetti147a,147b . E. Rossi105a,105b . L.P. Rossi51a . J.H.N. Rosten29. R. Rosten139. M. Rotaru27b. I. Roth172. J. Rothberg139. D. Rousseau118 . C.R. Royon137. A. Rozanov86. Y. Rozen153. X. Ruan146c. F. Rubbo144. I. Rubinskiy43 . V.I. Rud100. C. Rudolph45. M.S. Rudolph159. F. R¨uhr49. A. Ruiz-Martinez31. Z. Rurikova49 . N.A. Rusakovich66. A. Ruschke101. H.L. Russell139. J.P. Rutherfoord7. N. Ruthmann31 . Y.F. Ryabov124. M. Rybar166. G. Rybkin118. N.C. Ryder121. A. Ryzhov131. A.F. Saavedra151 . G. Sabato108. S. Sacerdoti28. A. Saddique3. H.F-W. Sadrozinski138. R. Sadykov66 . F. Safak Tehrani133a. P. Saha109. M. Sahinsoy59a. M. Saimpert137. T. Saito156. H. Sakamoto156 . Y. Sakurai171. G. Salamanna135a,135b . A. Salamon134a . J.E. Salazat Loyola33b. M. Saleem114 . D. Salek108. P.H. Sales Dg Bruin139. D. Salihagic102. A. Salnikov144. J. Salt167 . D. Salvatore38a,38b . F. Salvatore150. A. Salvucci61a. A. Salzburger31. D. Sammel49 . D. Sampsonidis155. A. Sanchez105a,105b . J. S´anchez167. V. Sanche— Martinez167. H. Sandaker120 . R.L. Sandbach77. H.G. Sander84. M.P. Sanders101. M. Sandhoff175. C. Sandoval20 . JHEP06(2016)093 R. Sandstroem102. D.P.C. Sankey132. M. Sannino51a,51b . A. Sansoni48. C. Santoni35 . R. Santonico134a,134b . H. Santos127a. I. Santoyq Castillo150. K. Sapp126. A. Sapronov66 . J.G. Saraiva127a,127d . B. Sarrazin22. O. Sasaki67. Y. Sasaki156. K. Sato161. G. Sauvage5,∗ . E. Sauvan5. G. Savage78. P. Savard159,d. C. Sawyer132. L. Sawyer80,o. J. Saxon32. C. Sbarra21a . A. Sbrizzi21a,21b . T. Scanlon79. D.A. Scannicchio163. M. Scarcella151. V. Scarfone38a,38b . J. Schaarschmidt172. P. Schacht102. D. Schaefer31. R. Schaefer43. J. Schaeffer84. S. Schaepe22 . S. Schaetzel59b. U. Sch¨afer84. A.C. Schaffer118. D. Schaile101. R.D. Schamberger149. V. Scharf59a . V.A. Schegelsky124. D. Scheirich130. M. Schernau163. C. Schiavi51a,51b . C. Schillo49 . M. Schioppa38a,38b . S. Schlenker31. K. Schmieden31. C. Schmitt84. S. Schmitt59b. S. Schmitt43 . B. Schneider160a. Y.J. Schnellbach75. U. Schnoor45. L. Schoeffel137. A. Schoening59b . B.D. Schoenrock91. E. Schopf22. A.L.S. Schorlemmer55. M. Schott84. D. Schouten160a . J. Schovancova8. S. Schramm50. M. Schreyer174. N. Schuh84. M.J. Schultens22 . H.-C. Schultz-Coulon59a. H. Schulz16. M. Schumacher49. B.A. Schumm138. Ph. Schune137 . C. Schwanenberger85. A. Schwartzman144. T.A. Schwarz90. Ph. Schwegler102. H. Schweiger85 . Ph. Schwemling137. R. Schwienhorst91. J. Schwindling137. T. Schwindt22. F.G. Sciacca17 . E. Scifo118. G. Sciolla24. F. Scuri125a,125b . F. Scutti22. J. Searcy90. G. Sedov43. E. Sedykh124 . P. Seema22. S.C. Seidel106. A. Seiden138. F. Seifert129. J.M. Seixas25a. G. Sekhniaidze105a . K. Sekhon90. S.J. Sekula41. D.M. Seliverstov124,∗. N. Semprini-Cesari21a,21b . C. Serfon31 . L. Serin118. L. Serkin164a,164b . T. Serre86. M. Sessa135a,135b . R. Seuster160a. H. Severini114 . T. Sfiligoj76. F. Sforza31. A. Sfyrla31. E. Shabalina55. M. Shamim117. L.Y. Shan34a. R. Shang166 . J.T. Shank23. M. Shapiro15. P.B. Shatalov98. K. Shaw164a,164b . S.M. Shaw85 . A. Shcherbakova147a,147b . C.Y. Shehu150. P. Sherwood79. L. Shi152,ai. S. Shimizu68 . C.O. Shimmin163. M. Shimojima103. M. Shiyakova66,aj . A. Shmeleva97. D. Shoalej Saadi96 . M.J. Shochet32. S. Shojaii92a,92b . S. Shrestha112. E. Shulga99. M.A. Shupe7. S. Shushkevich43 . P. Sicho128. P.E. Sidebo148. O. Sidiropoulou174. D. Sidorov115. A. Sidoti21a,21b . F. Siegert45 . Dj. Sijacki13. J. Silva127a,127d . Y. Silver154. S.B. Silverstein147a. V. Simak129. O. Simard5 . Lj. Simic13. S. Simion118. E. Simioni84. B. Simmons79. D. Simon35. P. Sinervo159. N.B. Sinev117 . olin147a,147b M. Sioli21a,21b . G. Siragusa174. A.N. Sisakyan66,∗. S.Yu. Sivoklokov100. J. Sj¨. T.B. Sjursen14. M.B. Skinner73. H.P. Skottowe58. P. Skubic114. M. Slater18. T. Slavicek129 . M. Slawinska108. K. Sliwa162. V. Smakhtin172. B.H. Smart47. L. Smestad14. S.Yu. Smirnov99 . Y. Smirnov99. L.N. Smirnova100,ak. O. Smirnova82. M.N.K. Smith36. R.W. Smith36 . M. Smizanska73. K. Smolek129. A.A. Snesarev97. G. Snidero77. S. Snyder26. R. Sobie169,l . F. Socher45. A. Soffer154. D.A. Soh152,ai. G. Sokhrannyi76. C.A. Solans Sanchez31. M. Solar129 . J. Solc129. E.Yu. Soldatov99. U. Soldevila167. A.A. Solodkov131. A. Soloshenko66 . O.V. Solovyanov131. V. Solovyev124. P. Sommer49. H.Y. Song34b,aa. N. Soni1. A. Sood15 . A. Sopczak129. B. Sopko129. V. Sopko129. V. Sorin12. D. Sosa59b. M. Sosebee8 . C.L. Sotiropoulou125a,125b . R. Soualah164a,164c . A.M. Soukharev110,c. D. South43. B.C. Sowden78 . 78 S. Spagnolo74a,74b . M. Spalla125a,125b . M. Spangenberg170. M. Spannowskyal. F. Span`o. W.R. Spearman58. D. Sperlich16. F. Spettel102. R. Spighi21a. G. Spigo31. L.A. Spiller89 . M. Spousta130. R.D. St. Denis54,∗. A. Stabile92a. S. Staerz45. J. Stahlman123. R. Stamen59a . S. Stamm16. E. Stanecka40. R.W. Stanek6. C. Stanescu135a. M. Stanescu-Bellu43 . M.M. Stanitzki43. S. Stapnes120. E.A. Starchenko131. J. Stark56. P. Staroba128. P. Starovoitov59a . R. Staszewski40. P. Steinberg26. B. Stelzer143. H.J. Stelzer31. O. Stelzer-Chilton160a. H. Stenzel53 . G.A. Stewart54. J.A. Stillings22. M.C. Stockton88. M. Stoebe88. G. Stoicea27b. P. Stolte55 . S. Stonjek102. A.R. Stradling8. A. Straessner45. M.E. Stramaglia17. J. Strandberg148 . S. Strandberg147a,147b . A. Strandlie120. E. Strauss144. M. Strauss114. P. Strizenec145b . R. Str¨ohmer174. D.M. Strom117. R. Stroynowski41. A. Strubig107. S.A. Stucci17. B. Stugu14 . N.A. Styles43. D. Su144. J. Su126. R. Subramaniam80. A. Succurro12. S. Suchek59a. Y. Sugaya119 . JHEP06(2016)093 M. Suk129. V.V. Sulin97. S. Sultansoy4c. T. Sumida69. S. Sun58. X. Sun34a. J.E. Sundermann49 . K. Suruliz150. G. Susinno38a,38b . M.R. Sutton150. S. Suzuki67. M. Svatos128. M. Swiatlowski144 . I. Sykora145a. T. Sykora130. D. Ta49. C. Taccini135a,135b . K. Tackmann43. J. Taenzer159 . A. Taffard163. R. Tafirout160a . N. Taiblum154. H. Takai26. R. Takashima70. H. Takeda68 . T. Takeshita141. Y. Takubo67. M. Talby86. A.A. Talyshev110,c. J.Y.C. Tam174. K.G. Tan89 . J. Tanaka156. R. Tanaka118. S. Tanaka67. B.B. Tannenwald112. N. Tannoury22 . S. Tapia Araya33b. S. Tapprogge84. S. Tarem153. F. Tarrade30. G.F. Tartarelli92a. P. Tas130 . M. Tasevsky128. T. Tashiro69. E. Tassi38a,38b . A. Tavares Delgado127a,127b . Y. Tayalati136d . F.E. Taylor95. G.N. Taylor89. P.T.E. Taylor89. W. Taylor160b. F.A. Teischinger31 . P. Teixeira-Dias78. K.K. Temming49. D. Temple143. H. Tep Kate31. P.K. Teng152. J.J. Teoh119 . F. Tepel175. S. Terada67. K. Terashi156. J. Terron83. S. Terzo102. M. Testa48. R.J. Teuscher159,l . T. Theveneaux-Pelzer35. J.P. Thomas18. J. Thomas-Wilsker78. E.N. Thompson36 . P.D. Thompson18. R.J. Thompson85. A.S. Thompson54. L.A. Thomsen176. E. Thomson123 . M. Thomson29. R.P. Thun90,∗. M.J. Tibbetts15. R.E. Ticsg Torres86. V.O. Tikhomirov97,am . Yu.A. Tikhonov110,c. S. Timoshenko99. E. Tiouchichine86. P. Tipton176. S. Tisserant86 . K. Todome158. T. Todorov5,∗. S. Todorova-Nova130. J. Tojo71. S. Tok´ar145a. K. Tokushuku67 . K. Tollefson91. E. Tolley58. L. Tomlinson85. M. Tomoto104. L. Tompkins144,an. K. Toms106 . E. Torrence117. H. Torres143. E. Torr´q Pastor139. J. Toth86,ao. F. Touchard86. D.R. Tovey140 . T. Trefzger174. L. Tremblet31. A. Tricoli31. I.M. Trigger160a. S. Trincaz-Duvoid81 . M.F. Tripiana12. W. Trischuk159. B. Trocm´e56. C. Troncon92a. M. Trottier-McDonald15 . M. Trovatelli169. L. Truong164a,164c . M. Trzebinski40. A. Trzupek40. C. Tsarouchas31 . J.C-L. Tseng121. P.V. Tsiareshka93. D. Tsionou155. G. Tsipolitis10. N. Tsirintanis9 . S. Tsiskaridze12. V. Tsiskaridze49. E.G. Tskhadadze52a. K.M. Tsui61a. I.I. Tsukerman98 . V. Tsulaia15. S. Tsuno67. D. Tsybychev149. A. Tudorache27b. V. Tudorache27b. A.N. Tuna58 . S.A. Tupputi21a,21b . S. Turchikhin100,ak. D. Turecek129. R. Turra92a,92b . A.J. Turvey41 . P.M. Tuts36. A. Tykhonov50. M. Tylmad147a,147b . M. Tyndel132. I. Ueda156. R. Ueno30 . M. Ughetto147a,147b . M. Ugland14. F. Ukegawa161. G. Unal31. A. Undrus26. G. Unel163 . F.C. Ungaro49. Y. Unno67. C. Unverdorben101. J. Urban145b. P. Urquijo89. P. Urrejola84 . G. Usai8. A. Usanova63. L. Vacavant86. V. Vacek129. B. Vachon88. C. Valderanis84 . N. Valencic108. S. Valentinetti21a,21b . A. Valero167. L. Valery12. S. Valkar130. S. Vallecorsa50 . J.A. Valls Ferrer167. W. Vap Dep Wollenberg108. P.C. Vap Det Deijl108. R. vap det Geer108 . H. vap det Graaf108. N. vap Eldik153. P. vap Gemmeren6. J. Vap Nieuwkoop143. I. vap Vulpen108 . M.C. vap Woerden31. M. Vanadia133a,133b . W. Vandelli31. R. Vanguri123. A. Vaniachine6 . F. Vannucci81. G. Vardanyan177. R. Vari133a. E.W. Varnes7. T. Varol41. D. Varouchas81 . A. Vartapetian8. K.E. Varvell151. F. Vazeille35. T. Vazque— Schroeder88. J. Veatch7 . L.M. Veloce159. F. Veloso127a,127c . T. Velz22. S. Veneziano133a . A. Ventura74a,74b . D. Ventura87 . M. Venturi169. N. Venturi159. A. Venturini24. V. Vercesi122a. M. Verducci133a,133b . W. Verkerke108. J.C. Vermeulen108. A. Vest45,ap. M.C. Vetterli143,d. O. Viazlo82. I. Vichou166 . T. Vickey140. O.E. Vickey Boeriu140. G.H.A. Viehhauser121. S. Viel15. R. Vigne63 . M. Villa21a,21b . M. Villaplana Perez92a,92b . E. Vilucchi48. M.G. Vincter30. V.B. Vinogradov66 . I. Vivarelli150. F. Vives Vaque3. S. Vlachos10. D. Vladoiu101. M. Vlasak129. M. Vogel33a . P. Vokac129. G. Volpi125a,125b . M. Volpi89. H. vop det Schmitt102. H. vop Radziewski49 . E. vop Toerne22. V. Vorobel130. K. Vorobev99. M. Vos167. R. Voss31. J.H. Vossebeld75 . N. Vranjes13. M. Vranjes Milosavljevic13. V. Vrba128. M. Vreeswijk108. R. Vuillermet31 . I. Vukotic32. Z. Vykydal129. P. Wagner22. W. Wagner175. H. Wahlberg72. S. Wahrmund45 . J. Wakabayashi104. J. Walder73. R. Walker101. W. Walkowiak142. C. Wang152. F. Wang173 . H. Wang15. H. Wang41. J. Wang43. J. Wang151. K. Wang88. R. Wang6. S.M. Wang152 . T. Wang22. T. Wang36. X. Wang176. C. Wanotayaroj117. A. Warburton88. C.P. Ward29 . JHEP06(2016)093 D.R. Wardrope79. A. Washbrook47. C. Wasicki43. P.M. Watkins18. A.T. Watson18 . I.J. Watson151. M.F. Watson18. G. Watts139. S. Watts85. B.M. Waugh79. S. Webb85 . M.S. Weber17. S.W. Weber174. J.S. Webster32. A.R. Weidberg121. B. Weinert62. J. Weingarten55 . C. Weiser49. H. Weits108. P.S. Wells31. T. Wenaus26. T. Wengler31. S. Wenig31. N. Wermes22 . M. Werner49. P. Werner31. M. Wessels59a. J. Wetter162. K. Whalen117. A.M. Wharton73 . A. White8. M.J. White1. R. White33b. S. White125a,125b . D. Whiteson163. F.J. Wickens132 . W. Wiedenmann173. M. Wielers132. P. Wienemann22. C. Wiglesworth37. L.A.M. Wiik-Fuchs22 . A. Wildauer102. H.G. Wilkens31. H.H. Williams123. S. Williams108. C. Willis91. S. Willocq87 . A. Wilson90. J.A. Wilson18. I. Wingerter-Seez5. F. Winklmeier117. B.T. Winter22. M. Wittgen144 . J. Wittkowski101. S.J. Wollstadt84. M.W. Wolter40. H. Wolters127a,127c . B.K. Wosiek40 . J. Wotschack31. M.J. Woudstra85. K.W. Wozniak40. M. Wu56. M. Wu32. S.L. Wu173. X. Wu50 . Y. Wu90. T.R. Wyatt85. B.M. Wynne47. S. Xella37. D. Xu34a. L. Xu26. B. Yabsley151 . S. Yacoob146a. R. Yakabe68. M. Yamada67. D. Yamaguchi158. Y. Yamaguchi119. A. Yamamoto67 . S. Yamamoto156. T. Yamanaka156. K. Yamauchi104. Y. Yamazaki68. Z. Yan23. H. Yang34e . H. Yang173. Y. Yang152. W-M. Yao15. Y.C. Yap81. Y. Yasu67. E. Yatsenko5. K.H. Yaw Wong22 . J. Ye41. S. Ye26. I. Yeletskikh66. A.L. Yen58. E. Yildirim43. K. Yorita171. R. Yoshida6 . K. Yoshihara123. C. Young144. C.J.S. Young31. S. Youssef23. D.R. Yu15. J. Yu8. J.M. Yu90 . J. Yu115. L. Yuan68. S.P.Y. Yuen22. A. Yurkewicz109. I. Yusuff29,aq . B. Zabinski40. R. Zaidan64 . A.M. Zaitsev131,ae. J. Zalieckas14. A. Zaman149. S. Zambito58. L. Zanello133a,133b . D. Zanzi89 . 145a C. Zeitnitz175. M. Zeman129. A. Zemla39a. Q. Zeng144. K. Zengel24. O. Zenin131. T. Zeniˇˇs. D. Zerwas118. D. Zhang90. F. Zhang173. G. Zhang34b. H. Zhang34c. J. Zhang6. L. Zhang49 . R. Zhang34b,j . X. Zhang34d. Z. Zhang118. X. Zhao41. Y. Zhao34d,118 . Z. Zhao34b . A. Zhemchugov66. J. Zhong121. B. Zhou90. C. Zhou46. L. Zhou36. L. Zhou41. M. Zhou149 . N. Zhou34f. C.G. Zhu34d. H. Zhu34a. J. Zhu90. Y. Zhu34b. X. Zhuang34a. K. Zhukov97 . A. Zibell174. D. Zieminska62. N.I. Zimine66. C. Zimmermann84. S. Zimmermann49. Z. Zinonos55 . M. Zinser84. M. Ziolkowski142,L. ˇc, Zivkovi´13. G. Zobernig173. A. Zoccoli21a,21b . M. zut Nedden16 G. Zurzolo105a,105b and L. Zwalinski31 . 1 Department of Physics, University of Adelaide, Adelaide, Australia 2 Physics Department, SUNY Albany, Albany NY, U.S.A. 3 Department of Physics, University of Alberta, Edmonton AB, Canada 4(a) Department of Physics, Ankara University, Ankara; (b) Istanbul Aydin University, Istanbul; (c) Division of Physics, TOBB University of Economics and Technology, Ankara, Turkey 5 LAPP, CNRS/IN2P3 and Universit´e Savoie Mont Blanc, Annecy-le-Vieux, France 6 High Energy Physics Division, Argonne National Laboratory, Argonne IL, U.S.A. 7 Department of Physics, University of Arizona, Tucson AZ, U.S.A. 8 Department of Physics, The University of Texas at Arlington, Arlington TX, U.S.A. 9 Physics Department, University of Athens, Athens, Greece 10 Physics Department, National Technical University of Athens, Zografou, Greece 11 Institute of Physics, Azerbaijan Academy of Sciences, Baku, Azerbaijan 12 Institut de F´ısica d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology, Barcelona, Spain, Spain 13 Institute of Physics, University of Belgrade, Belgrade, Serbia 14 Department for Physics and Technology, University of Bergen, Bergen, Norway 15 Physics Division, Lawrence Berkeley National Laboratory and University of California, Berkeley CA, U.S.A. 16 Department of Physics, Humboldt University, Berlin, Germany 17 Albert Einstein Center for Fundamental Physics and Laboratory for High Energy Physics, University of Bern, Bern, Switzerland 18 School of Physics and Astronomy, University of Birmingham, Birmingham, U.K. JHEP06(2016)093 19 (a) Department of Physics, Bogazici University, Istanbul; (b) Department of Physics Engineering, Gaziantep University, Gaziantep; (c) Department of Physics, Dogus University, Istanbul, Turkey 20 Centro de Investigaciones, Universidad Antonio Narino, Bogota, Colombia 21 (a) INFN Sezione di Bologna; (b) Dipartimento di Fisica e Astronomia, Universit`a di Bologna, Bologna, Italy 22 Physikalisches Institut, University of Bonn, Bonn, Germany 23 Department of Physics, Boston University, Boston MA, U.S.A. 24 Department of Physics, Brandeis University, Waltham MA, U.S.A. 25 (a) Universidade Federal do Rio De Janeiro COPPE/EE/IF, Rio de Janeiro; (b) Electrical Circuits Department,FederalUniversity of Juiz deFora(UFJF), Juiz deFora; (c) Federal University of Sao Joao del Rei (UFSJ), Sao Joao del Rei; (d) Instituto de Fisica,Universidade de Sao Paulo, Sao Paulo, Brazil 26 Physics Department, Brookhaven National Laboratory, Upton NY, U.S.A. 27 (a) Transilvania University of Brasov, Brasov, Romania; (b) National Institute of Physics and Nuclear Engineering, Bucharest; (c) National Institute for Research and Development of Isotopic and Molecular Technologies, Physics Department, Cluj Napoca; (d) University Politehnica Bucharest, Bucharest; (e)] West University in Timisoara, Timisoara, Romania 28 Departamento de F´ısica, Universidad de Buenos Aires, Buenos Aires, Argentina 29 Cavendish Laboratory, University of Cambridge, Cambridge, U.K. 30 Department of Physics, Carleton University, Ottawa ON, Canada 31 CERN, Geneva, Switzerland 32 Enrico Fermi Institute, University of Chicago, Chicago IL, U.S.A. 33 (a) Departamento deF´ısica, Pontificia Universidad Cat´olica de Chile, Santiago; (b) Departamento 34] de F´ısica, Universidad T´ecnica Federico Santa Mar´ıa, Valpara´ıso, Chile (a) Institute of High Energy Physics, Chinese Academy of Sciences, Beijing; (b) Department of Modern Physics, University of Science and Technology of China, Anhui; (c) Department of Physics, Nanjing University, Jiangsu; (d) School of Physics, Shandong University, Shandong; (e) Department of Physics and Astronomy, Shanghai Key Laboratory for Particle Physics and Cosmology, Shanghai JiaoTongUniversity, Shanghai; (also affiliated with PKU-CHEP); (f) Physics Department, Tsinghua University, Beijing 100084, China 35 Laboratoire de Physique Corpusculaire, Clermont Universit´e and Universit´e Blaise Pascal and CNRS/IN2P3, Clermont-Ferrand, France 36 Nevis Laboratory, Columbia University, Irvington NY, U.S.A. 37 Niels Bohr Institute, University of Copenhagen, Kobenhavn, Denmark 38 (a) INFN Gruppo Collegato di Cosenza, Laboratori Nazionali di Frascati; (b) Dipartimento di Fisica, Universit`a della Calabria, Rende, Italy 39 (a) AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Krakow; (b) Marian Smoluchowski Institute of Physics, Jagiellonian University, Krakow, Poland 40 Institute of Nuclear Physics Polish Academy of Sciences, Krakow, Poland 41 Physics Department, Southern MethodistUniversity, Dallas TX,U.S.A. 42 Physics Department, University ofTexas at Dallas,Richardson TX,U.S.A. 43 DESY, Hamburg and Zeuthen, Germany 44 Institut f¨ur Experimentelle Physik IV, Technische Universit¨at Dortmund, Dortmund, Germany 45 Institut f¨ur Kern-und Teilchenphysik, Technische Universit¨at Dresden, Dresden, Germany 46 Department of Physics, Duke University, Durham NC, U.S.A. 47 SUPA -School of Physics and Astronomy, University of Edinburgh, Edinburgh, U.K. 48 INFN Laboratori Nazionali di Frascati, Frascati, Italy 49 Fakult¨at f¨ur Mathematik und Physik, Albert-Ludwigs-Universit¨at, Freiburg, Germany 50 Section de Physique, Universit´e de Gen`eve, Geneva, Switzerland 51 (a) INFN Sezione di Genova; (b) Dipartimento di Fisica, Universit`a di Genova, Genova, Italy 52 (a)(b) E. Andronikashvili Institute of Physics, Iv. Javakhishvili Tbilisi State University, Tbilisi; High Energy Physics Institute, Tbilisi State University, Tbilisi, Georgia JHEP06(2016)093 53 II Physikalisches Institut, Justus-Liebig-Universit¨at Giessen, Giessen, Germany 54 SUPA -School of Physics and Astronomy, University of Glasgow, Glasgow, U.K. 55 II Physikalisches Institut, Georg-August-Universit¨at, G¨ottingen, Germany 56 Laboratoire de Physique Subatomique et de Cosmologie, Universit´e Grenoble-Alpes, CNRS/IN2P3, Grenoble, France 57 Department of Physics, Hampton University, Hampton VA, U.S.A. 58 Laboratory for Particle Physics and Cosmology, Harvard University, Cambridge MA, U.S.A. 59 (a) Kirchhoff-Institut f¨ur Physik, Ruprecht-Karls-Universit¨at Heidelberg, Heidelberg; (b) Physikalisches Institut, Ruprecht-Karls-Universit¨at Heidelberg, Heidelberg; (c) ZITI Institut f¨ur technische Informatik, Ruprecht-Karls-Universit¨at Heidelberg, Mannheim, Germany 60 Faculty of Applied Information Science, Hiroshima Institute of Technology, Hiroshima, Japan 61 (a) Department of Physics, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong; (b) Department of Physics, The University of Hong Kong, Hong Kong; (c) Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China 62 Department of Physics, Indiana University, Bloomington IN, U.S.A. 63 Institut f¨ur Astro-und Teilchenphysik, Leopold-Franzens-Universit¨at, Innsbruck, Austria 64 University of Iowa, Iowa City IA, U.S.A. 65 Department of Physics and Astronomy, Iowa State University, Ames IA, U.S.A. 66 Joint Institute for Nuclear Research, JINR Dubna, Dubna, Russia 67 KEK, High Energy Accelerator Research Organization, Tsukuba, Japan 68 Graduate School of Science, Kobe University, Kobe, Japan 69 Faculty of Science, Kyoto University, Kyoto, Japan 70 Kyoto University of Education, Kyoto, Japan 71 Department of Physics, Kyushu University, Fukuoka, Japan 72 Instituto de F´ısica La Plata, Universidad Nacional de La Plata and CONICET, La Plata, Argentina 73 Physics Department, Lancaster University, Lancaster, U.K. 74 (a) INFN Sezione di Lecce; (b) Dipartimento di Matematica e Fisica, Universit`a del Salento, Lecce, Italy 75 Oliver Lodge Laboratory, University of Liverpool, Liverpool, U.K. 76 Department of Physics, Joˇzef Stefan Institute and University of Ljubljana, Ljubljana, Slovenia 77 School of Physics and Astronomy, Queen Mary University of London, London, U.K. 78 Department of Physics,RoyalHollowayUniversity ofLondon, Surrey,U.K. 79 Department of Physics and Astronomy, University College London, London, U.K. 80 Louisiana Tech University, Ruston LA, U.S.A. 81 Laboratoire de Physique Nucl´eaire et de Hautes Energies, UPMC and Universit´e Paris-Diderot and CNRS/IN2P3, Paris, France 82 Fysiska institutionen, Lunds universitet, Lund, Sweden 83 Departamento de Fisica Teorica C-15, Universidad Autonoma de Madrid, Madrid, Spain 84 Institut f¨ur Physik, Universit¨at Mainz, Mainz, Germany 85 School of Physics and Astronomy, University of Manchester, Manchester, U.K. 86 CPPM, Aix-Marseille Universit´e and CNRS/IN2P3, Marseille, France 87 Department of Physics, University of Massachusetts, Amherst MA, U.S.A. 88 Department of Physics, McGill University, Montreal QC, Canada 89 School of Physics, University of Melbourne, Victoria, Australia 90 Department of Physics, The University of Michigan, Ann Arbor MI, U.S.A. 91 Department of Physics and Astronomy, Michigan State University, East Lansing MI, U.S.A. 92 (a) INFN Sezione di Milano; (b) Dipartimento di Fisica, Universit`a di Milano, Milano, Italy 93 B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk, Republic of Belarus 94 National Scientific and Educational Centre for Particle and High Energy Physics, Minsk, Republic of Belarus 95 Department of Physics, Massachusetts Institute of Technology, Cambridge MA, U.S.A. JHEP06(2016)093 96 Group of Particle Physics, University of Montreal, Montreal QC, Canada 97 P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Moscow, Russia 98 Institute for Theoretical and Experimental Physics (ITEP), Moscow, Russia 99 National Research Nuclear University MEPhI, Moscow, Russia 100 D.V. Skobeltsyn Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Moscow, Russia 101 Fakult¨at f¨ur Physik, Ludwig-Maximilians-Universit¨at M¨unchen, M¨unchen, Germany 102 Max-Planck-Institut f¨ur Physik (Werner-Heisenberg-Institut), M¨unchen, Germany 103 Nagasaki Institute of Applied Science, Nagasaki, Japan 104 Graduate School of Science and Kobayashi-Maskawa Institute, Nagoya University, Nagoya, Japan 105 (a) INFN Sezione di Napoli; (b) Dipartimento di Fisica, Universit`a di Napoli, Napoli, Italy 106 Department of Physics and Astronomy, University of New Mexico, Albuquerque NM, U.S.A. 107 Institute for Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen/Nikhef, Nijmegen, Netherlands 108 Nikhef National Institute for Subatomic Physics and University of Amsterdam, Amsterdam, Netherlands 109 Department of Physics, Northern Illinois University, DeKalb IL, U.S.A. 110 Budker Institute of Nuclear Physics, SB RAS, Novosibirsk, Russia 111 Department of Physics, New York University, New York NY, U.S.A. 112 Ohio State University, Columbus OH, U.S.A. 113 Faculty of Science, Okayama University, Okayama, Japan 114 Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman OK, U.S.A. 115 Department of Physics, Oklahoma State University, Stillwater OK, U.S.A. 116 Palack´y University, RCPTM, Olomouc, Czech Republic 117 Center for High Energy Physics, University of Oregon, Eugene OR, U.S.A. 118 LAL, Univ. Paris-Sud, CNRS/IN2P3, Universit´e Paris-Saclay, Orsay, France 119 Graduate School of Science, Osaka University, Osaka, Japan 120 Department of Physics, University of Oslo, Oslo, Norway 121 Department of Physics, Oxford University, Oxford, U.K. 122 (a) INFN Sezione di Pavia; (b) Dipartimento di Fisica, Universit`a di Pavia, Pavia, Italy 123 Department of Physics, University of Pennsylvania, Philadelphia PA, U.S.A. 124 National Research Centre ”Kurchatov Institute” B.P.Konstantinov Petersburg Nuclear Physics Institute, St. Petersburg, Russia 125 (a) INFN Sezione di Pisa; (b) Dipartimento di Fisica E. Fermi, Universit`a di Pisa, Pisa, Italy 126 Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh PA, U.S.A. 127 (a) Laborat´orio de Instrumenta¸c˜ao e F´ısica Experimental de Part´ıculas -LIP, Lisboa; (b) Faculdade de Ciˆencias, Universidade de Lisboa, Lisboa; (c) Department of Physics, University of Coimbra, Coimbra; (d) Centro de F´ısica Nuclear da Universidade de Lisboa, Lisboa; (e) Departamento de Fisica, Universidade do Minho, Braga; (f) Departamento de Fisica Teorica y del Cosmos and CAFPE, Universidad de Granada, Granada (Spain); (g) Dep Fisica and CEFITEC of Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal 128 Institute of Physics, Academy of Sciences of the Czech Republic, Praha, Czech Republic 129 Czech Technical University in Prague, Praha, Czech Republic 130 Faculty of Mathematics and Physics, Charles University in Prague, Praha, Czech Republic 131 State Research Center Institute for High Energy Physics (Protvino), NRC KI, Russia 132 Particle Physics Department, Rutherford Appleton Laboratory, Didcot, U.K. 133 (a) INFN Sezione di Roma; (b) Dipartimento di Fisica, Sapienza Universit`a di Roma, Roma, Italy 134 (a) INFN Sezione di Roma Tor Vergata; (b) Dipartimento di Fisica, Universit`a di Roma Tor Vergata, Roma, Italy 135 (a) INFN Sezione di Roma Tre; (b) Dipartimento di Matematica e Fisica, Universit`a Roma Tre, Roma, Italy JHEP06(2016)093 136 (a) Facult´e des Sciences Ain Chock, R´eseau Universitaire de Physique des Hautes Energies Universit´e Hassan II, Casablanca; (b) Centre National de l’Energie des Sciences Techniques Nucleaires, Rabat; (c) Facult´e des Sciences Semlalia, Universit´e Cadi Ayyad, LPHEA-Marrakech; (d) Facult´e des Sciences, Universit´e Mohamed Premier and LPTPM, Oujda; (e) Facult´e des sciences, Universit´e Mohammed V, Rabat, Morocco 137 DSM/IRFU (Institut de Recherches sur les Lois Fondamentales de l’Univers), CEA Saclay (Commissariat ` a l’Energie Atomique et aux Energies Alternatives), Gif-sur-Yvette, France 138 Santa Cruz Institute for Particle Physics, University of California Santa Cruz, Santa Cruz CA, U.S.A. 139 Department of Physics, University of Washington, Seattle WA, U.S.A. 140 Department of Physics andAstronomy,University of Sheffield, Sheffield,U.K. 141 Department of Physics, Shinshu University, Nagano, Japan 142 Fachbereich Physik, Universit¨at Siegen, Siegen, Germany 143 Department of Physics, Simon Fraser University, Burnaby BC, Canada 144 SLAC National Accelerator Laboratory, Stanford CA, U.S.A. 145 (a) Faculty of Mathematics, Physics & Informatics, Comenius University, Bratislava; (b) Department of Subnuclear Physics, Institute of Experimental Physics of the Slovak Academy of Sciences, Kosice, Slovak Republic 146 (a) Department of Physics, University of Cape Town, Cape Town; (b) Department of Physics, University of Johannesburg, Johannesburg; (c) School of Physics, University of the Witwatersrand, Johannesburg, South Africa 147 (a) Department of Physics, Stockholm University; (b) The Oskar Klein Centre, Stockholm, Sweden 148 Physics Department, Royal Institute of Technology, Stockholm, Sweden 149 Departments of Physics & Astronomy and Chemistry, Stony Brook University, Stony Brook NY, U.S.A. 150 Department of Physics and Astronomy, University of Sussex, Brighton, U.K. 151 School of Physics, University of Sydney, Sydney, Australia 152 Institute of Physics, Academia Sinica, Taipei, Taiwan 153 Department of Physics, Technion: Israel Institute of Technology, Haifa, Israel 154 Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel 155 Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, Greece 156 International Center for Elementary Particle Physics and Department of Physics, The University of Tokyo, Tokyo, Japan 157 Graduate School of Science and Technology, Tokyo Metropolitan University, Tokyo, Japan 158 Department of Physics, Tokyo Institute of Technology, Tokyo, Japan 159 Department of Physics, University of Toronto, Toronto ON, Canada 160 (a) TRIUMF, Vancouver BC; (b) Department of Physics and Astronomy, York University, Toronto ON, Canada 161 Faculty of Pure and Applied Sciences, and Center for Integrated Research in Fundamental Science and Engineering, University of Tsukuba, Tsukuba, Japan 162 Department of Physics and Astronomy, Tufts University, Medford MA, U.S.A. 163 Department of Physics and Astronomy, University of California Irvine, Irvine CA, U.S.A. 164 (a) INFN Gruppo Collegato di Udine, Sezione di Trieste, Udine; (b) ICTP, Trieste; (c) Dipartimento di Chimica, Fisica e Ambiente, Universit`a di Udine, Udine, Italy 165 Department of Physics and Astronomy, University of Uppsala, Uppsala, Sweden 166 Department of Physics, University of Illinois, Urbana IL, U.S.A. 167 Instituto de F´ısica Corpuscular (IFIC) and Departamento de F´ısica At´omica, Molecular y Nuclear and Departamento de Ingenier´ıa Electr´onica and Instituto de Microelectr´onica de Barcelona (IMB-CNM), University of Valencia and CSIC, Valencia, Spain 168 Department of Physics, University of British Columbia, Vancouver BC, Canada 169 Department of Physics and Astronomy, University of Victoria, Victoria BC, Canada JHEP06(2016)093 170 Department of Physics, University of Warwick, Coventry, U.K. 171 Waseda University, Tokyo, Japan 172 Department of Particle Physics, The Weizmann Institute of Science, Rehovot, Israel 173 Department of Physics, University of Wisconsin, Madison WI, U.S.A. 174 Fakult¨at f¨ur Physik und Astronomie, Julius-Maximilians-Universit¨at, W¨urzburg, Germany 175 Fakult¨at f¨ur Mathematik und Naturwissenschaften, Fachgruppe Physik, Bergische Universit¨at Wuppertal, Wuppertal, Germany 176 Department of Physics, Yale University, New Haven CT, U.S.A. 177 Yerevan Physics Institute, Yerevan, Armenia 178 Centre de Calcul de l’Institut National de Physique Nucl´eaire et de Physique des Particules (IN2P3), Villeurbanne, France a Also at Department of Physics, King’s College London, London, U.K. b Also at Institute of Physics, Azerbaijan Academy of Sciences, Baku, Azerbaijan c Also at Novosibirsk State University, Novosibirsk, Russia d Also at TRIUMF, Vancouver BC, Canada e Also at Department of Physics, California State University, Fresno CA, U.S.A. f Also at Department of Physics, University of Fribourg, Fribourg, Switzerland g Also at Departament de Fisica de la Universitat Autonoma de Barcelona, Barcelona, Spain h Also at Departamento de Fisica e Astronomia, Faculdade de Ciencias, Universidade do Porto, Portugal i Also at Tomsk State University, Tomsk, Russia j Also at CPPM, Aix-Marseille Universit´e and CNRS/IN2P3, Marseille, France k Also at Universita di Napoli Parthenope, Napoli, Italy l Also at Institute of Particle Physics (IPP), Canada m Also at Particle Physics Department, Rutherford Appleton Laboratory, Didcot, U.K. n Also at Department of Physics, St. Petersburg State Polytechnical University, St. Petersburg, Russia o Also at Louisiana Tech University, Ruston LA, U.S.A. p Also at Institucio Catalana de Recerca i Estudis Avancats, ICREA, Barcelona, Spain q Also at Department of Physics, The University of Michigan, Ann Arbor MI, U.S.A. r Also at Graduate School of Science, Osaka University, Osaka, Japan s Also at Department of Physics, National Tsing Hua University, Taiwan t Also at Department of Physics, The University of Texas at Austin, Austin TX, U.S.A. u Also at Institute of Theoretical Physics, Ilia State University, Tbilisi, Georgia v Also at CERN, Geneva, Switzerland w Also at Georgian Technical University (GTU),Tbilisi, Georgia x Also at Ochadai Academic Production, Ochanomizu University, Tokyo, Japan y Also at Manhattan College, New York NY, U.S.A. z Also atHellenicOpenUniversity, Patras,Greece aa Also at Institute of Physics, Academia Sinica, Taipei, Taiwan ab Also at LAL, Univ. Paris-Sud, CNRS/IN2P3, Universit´e Paris-Saclay, Orsay, France ac Also at Academia Sinica Grid Computing, Institute of Physics, Academia Sinica, Taipei, Taiwan ad Also at School of Physics, Shandong University, Shandong, China ae Also at Moscow Institute of Physics and Technology State University, Dolgoprudny, Russia af Also at Section de Physique, Universit´e de Gen`eve, Geneva, Switzerland ag Also at International School for Advanced Studies (SISSA), Trieste, Italy ah Also at Department of Physics and Astronomy, University of South Carolina, Columbia SC, U.S.A. ai Also at School of Physics and Engineering, Sun Yat-sen University, Guangzhou, China aj Also at Institute for Nuclear Research and Nuclear Energy (INRNE) of the Bulgarian Academy of Sciences, Sofia, Bulgaria ak Also at Faculty of Physics, M.V.Lomonosov Moscow State University, Moscow, Russia JHEP06(2016)093 al Associated at Durham University, IPPP, Durham, U.K. am Also at National Research Nuclear University MEPhI, Moscow, Russia an Also at Department of Physics, Stanford University, Stanford CA, U.S.A. ao Also at Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Budapest, Hungary ap Also at Flensburg University of Applied Sciences, Flensburg, Germany aq Also at University of Malaya, Department of Physics, Kuala Lumpur, Malaysia ∗ Deceased ― 82 ― JHEP06(2016)093