Back to Search Start Over

Magnetic field induced polarization difference between hyperons and anti-hyperons

Authors :
Yu Guo
Shuzhe Shi
Shengqin Feng
Jinfeng Liao
Source :
Physics Letters B, Vol 798, Iss , Pp - (2019)
Publication Year :
2019
Publisher :
Elsevier, 2019.

Abstract

Recent STAR measurements suggest a difference in the global spin polarization between hyperons and anti-hyperons, especially at relatively low collision beam energy. One possible cause of this difference is the potential presence of in-medium magnetic field. In this study, we investigate the phenomenological viability of this interpretation. Using the AMPT model framework, we quantify the influence of different magnetic field evolution scenarios on the size of the polarization difference in a wide span of collision beam energies. We find that such difference is very sensitive to the lifetime of the magnetic field. For the same lifetime, the computed polarization difference only mildly depends on the detailed form of its evolution. Assuming magnetic polarization as the mechanism to enhance anti-hyperon signal while suppress hyperon signal, we phenomenologically extract an upper limit on the needed magnetic field lifetime in order to account for the experimental data. The so-obtained lifetime values are in a quite plausible ballpark and follow approximately the scaling relation of being inversely proportional to the beam energy. Possible implications on other magnetic field related effects are also discussed. Keywords: Heavy ion collision, Vorticity, Global polarization, Magnetic field

Subjects

Subjects :
Physics
QC1-999

Details

Language :
English
ISSN :
03702693
Volume :
798
Issue :
-
Database :
Directory of Open Access Journals
Journal :
Physics Letters B
Publication Type :
Academic Journal
Accession number :
edsdoj.92cd70f6e93b47b3bcbff6fb3199a096
Document Type :
article
Full Text :
https://doi.org/10.1016/j.physletb.2019.134929