Interpretation of $\Lambda$ spin polarization measurements

Bibliographic description

punktacja MEiN [2022]: 140

title:	Interpretation of $\Lambda$ spin polarization measurements
author:	Florkowski Wojciech , Ryblewski Radoslaw
journal title:	Physical Review. C
volume:	106
issue:	2
date of publication :	2022
article ID:	024905
ISSN:	2469-9985
eISSN:	2469-9993
DOI:	10.1103/PhysRevC.106.024905
language:	English
journal language:	English
abstract in English:	The physics interpretation of the recent measurements of the spin polarization of $\Lambda$ hyperons produced in relativistic heavy-ion collisions is discussed. We suggest that the polarization measured in the $\Lambda$ rest frame should be projected along the direction of the total angular momentum that is first transformed to the same frame, and only then averaged over $\Lambda 's$ with different momenta in the center-of-mass frame. While this procedure does not affect the current measurements done in a broad transverse-momentum range, it may become important (representing a correction of about 10%) for the most energetic hyperons under study (with transverse momenta reaching 4-5 GeV / c). The proposed treatment is generally more appropriate for relativistic $\Lambda 's$. Throughout the paper, we deliver explicit expressions for various boosts, rotations, and transformations of angular distributions, which may help to compare model predictions with the experimental results.
affiliation:	Wydział Fizyki, Astronomii i Informatyki Stosowanej : Instytut Fizyki Teoretycznej
type:	journal article
subtype:	academic paper