Effects of quark chemical equilibration on thermal photon elliptic flow

Hot Quarks 2014: Workshop for young scientists on the physics of ultrarelativistic nucleus-nucleus collisions

Monnai, Akihiko^1

RIKEN BNL Research Center, Brookhaven National Laboratory, Upton

NY

11973, United States^1

关键词: Direct photons;    Elliptic flows;    Equilibration process;    High energy heavy-ion collision;    Thermal photons;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/612/1/012026/pdf
DOI  :  10.1088/1742-6596/612/1/012026

来源: IOP

【 摘 要 】

Large hadronic elliptic flow v2is considered as an evidence for the existence of a strongly-coupled QGP fluid in high-energy heavy-ion collisions. On the other hand, direct photon v2has recently been found to be much larger than that of hydrodynamic estimations, which is recognized as "photon v2puzzle". In this study, I discuss the implication of late production of quarks in an initially gluon-rich medium because photons are coupled to quarks. Numerical analyses imply that thermal photon v2can be visibly enhanced. This indicates that interplay of equilibration processes and collective expansion would be important.