Description
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Title: Spin Hydrodynamics from Both Microscopic and Macroscopic Approaches
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Abstract:
As a conserved quantity in the evolution of the quark-gluon plasma (QGP) created in heavy-ion collisions, the total angular momentum consists of two sectors: the orbital angular momentum (OAM) caused by kinetic motion, and the intrinsic spin angular momentum of quarks and gluons. In a heavy-ion collision event, the system starts with finite OAM but un-polarized spin density (unless prepared specifically). Microscopic scattering processes allow a coupling between these two components. Therefore, spin polarization can eventually develop and may have a non-trivial influence on the QGP evolution. A hydrodynamic theory, with the aforementioned spin polarization effect properly taken into account, is required, especially for quantitative studies of the polarization rate of observed hadrons, e.g. $\Lambda$-hyperon.The latter has been observed in RHIC experiment, serving as an evidence of the most vortical fluid in the universe. In this talk, we will construct the dissipative spin hydrodynamics from two approaches -- from (microscopic) kinetic theory, and from macroscopic principles.
Firstly, we start with chiral kinetic theory and construct the {\bf spin hydrodynamic framework} for a chiral spinor system. We obtain the equations of motion of second-order dissipative relativistic fluid dynamics with non-trivial spin polarization density. In a chiral spinor system, the spin alignment effect could be treated in the same framework as for Chiral Vortical Effect (CVE). However, the fluid vorticity induces not only the CVE current but also asymmetric stress tensor as well as spin polarization of final state hadrons, all of which emerge as quantum corrections.
Then, we will compare the results with what one can get from macroscopic principles, i.e. conservation laws and second law of thermodynamics. Compared to previous results from the same approach, we find extra terms could exist without violating the aforementioned macroscopic principles.
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CV:
currently a PostDoc at McGill University, working with Dr. Charles Gale and Sangyong Jeon.
I obtained my M.S. from Tsinghua University (with Dr. Pengfei Zhuang) and Ph.D. from Indiana University, Bloomington (with Dr. Jinfeng Liao).
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Primary author
Shuzhe Shi
(McGill University)
