Relaxation time for the alignment between the spin of a finite-mass quark or antiquark and the thermal vorticity in relativistic heavy-ion collisions

被引:18
作者
Ayala, Alejandro [1 ,2 ,3 ]
de la Cruz, David [4 ]
Hernandez, L. A. [1 ,2 ,3 ,5 ]
Salinas, Jordi [1 ]
机构
[1] Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Apartado Postal 70-543, Mexico City 04510, DF, Mexico
[2] Univ Cape Town, Ctr Theoret & Math Phys, ZA-7700 Rondebosch, South Africa
[3] Univ Cape Town, Dept Phys, ZA-7700 Rondebosch, South Africa
[4] Inst Politecn Nacl, Dept Fis, Escuela Super Fis & Matemat, Unidad Adolfo Lopez Mateos, Edificio 9, Mexico City 07738, DF, Mexico
[5] Univ Autonoma Tlaxcala, Fac Ciencias Educ, Tlaxcala 90000, Mexico
关键词
LAMBDA HYPERON POLARIZATION;
D O I
10.1103/PhysRevD.102.056019
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We study the relaxation time required for the alignment between the spin of a finite-mass quark or antiquark and the thermal vorticity, at finite temperature and baryon chemical potential, in the context of relativistic heavy-ion collisions. The relaxation time is computed as the inverse of the total reaction rate that in turn is obtained from the imaginary part of the quark or antiquark self-energy. We model the interaction between spin and thermal vorticity within the medium by means of a vertex coupling quarks and thermal gluons that, for a uniform temperature, is proportional to the global angular velocity and inversely proportional to the temperature. We use realistic estimates for the angular velocities for different collision energies and show that the effect of the quark mass is to reduce the relaxation times as compared to the massless quark case. Using these relaxation times we estimate the intrinsic quark and antiquark polarizations produced by the thermal vorticity. We conclude by pointing out that, although the intrinsic global polarization of the s-quark turns out to be larger than that of the (s) over bar -quark, there is room to explain recent STAR results which show that the global polarization of (Lambda) over bar is larger than that of Lambda when considering that these hyperons can be produced from different density regions in a core-corona model.
引用
收藏
页数:7
相关论文
共 38 条
[31]   Axial anomaly and energy dependence of hyperon polarization in heavy-ion collisions [J].
Sorin, Alexander ;
Teryaev, Oleg .
PHYSICAL REVIEW C, 2017, 95 (01)
[32]   P-odd effects in heavy ion collisions at NICA [J].
Sorin, Alexander ;
Teryaev, Oleg .
NUCLEAR AND PARTICLE PHYSICS PROCEEDINGS, 2016, 273 :2587-2589
[33]   Λ hyperon polarization in relativistic heavy ion collisions from a chiral kinetic approach [J].
Sun, Yifeng ;
Ko, Che Ming .
PHYSICAL REVIEW C, 2017, 96 (02)
[34]   A Monte Carlo Study of Lambda Hyperon Polarization at BM@N [J].
Suvarieva D. ;
Gudima K. ;
Zinchenko A. .
Physics of Particles and Nuclei Letters, 2018, 15 (2) :182-188
[35]   Probing vorticity structure in heavy-ion collisions by local A polarization [J].
Xia, Xiao-Liang ;
Li, Hui ;
Tang, Zebo ;
Wang, Qun .
PHYSICAL REVIEW C, 2018, 98 (02)
[36]   Λ polarization in peripheral collisions at moderately relativistic energies [J].
Xie, Y. L. ;
Bleicher, M. ;
Stoecker, H. ;
Wang, D. J. ;
Csernai, L. P. .
PHYSICAL REVIEW C, 2016, 94 (05)
[37]   Λ polarization in an exact rotating and expanding fluid dynamical model for peripheral heavy ion reactions [J].
Xie, Yilong ;
Glastad, Robert C. ;
Csernai, Laszlo P. .
PHYSICAL REVIEW C, 2015, 92 (06)
[38]  
Xie YL, 2020, EUR PHYS J C, V80, DOI 10.1140/epjc/s10052-019-7576-8