Shear induced polarization: collisional contributions

Journal of High Energy Physics

Regular Article - Theoretical Physics

Ziyue Wang¹  Shu Lin² 

[1] Faculty of Science, Beijing University of Technology, 100021, Beijing, China;Department of Physics, Tsinghua University, 100084, Beijing, China;School of Physics and Astronomy, Sun Yat-Sen University, 519082, Zhuhai, China;

关键词: Finite Temperature or Finite Density;    Quark-Gluon Plasma;   

DOI  :  10.1007/JHEP12(2022)030

 received in 2022-07-06, accepted in 2022-11-24,  发布年份 2022

来源: Springer

【 摘 要 】

It has been realized that thermal shear plays a similar role as thermal vorticity in polarizing spin of particles in heavy ion collisions. We point out that shear has a funda- mental difference that it leads to particle redistribution in the medium. The redistribution gives rise to an additional contribution to spin polarization through the self-energy, which is parametrically the same order as the one considered so far in the literature. The self-energy contribution is in general gauge dependent. We introduce double gauge links stretching along the Schwinger-Keldysh contour to restore gauge invariance. We also generalize the straight path to adapt to the Schwinger-Keldysh contour. We find another contribution associated with the gauge link, which is also parametrically the same order. We illustrate the two contributions with a massive probe fermion in massless QED plasma with shear. A modest suppression of spin polarization is found from the combined contributions when the probe fermion has momentum much greater than the temperature.

【 授权许可】

Unknown   
© The Author(s) 2022

【 图 表 】

Fig. 2