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

Abstract

We study the relaxation time required for the alignment between the spin of a finite-mass quark/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/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, in spite of the former being larger than the latter, it is still possible to understand recent results from the STAR Beam Energy Scan when accounting for the fact that only a portion of quarks/antiquarks come from the denser and thus thermalized region in the collision.

arXiv comment6 pages, 7 figures. Expanded discussion, conclusions unchanged. arXiv admin note: text overlap with arXiv:1909.00274

References in corpus (32)

• Microscopic Models for Ultrarelativistic Heavy Ion Collisions
• Relativistic Hadron-Hadron Collisions in the Ultra-Relativistic Quantum Molecular Dynamics Model (UrQMD)
• Global $\Lambda$ hyperon polarization in nuclear collisions: evidence for the most vortical fluid
• Comparison of Chemical Freeze-Out Criteria in Heavy-Ion Collisions
• Globally Polarized Quark-gluon Plasma in Non-central A+A Collisions
• Angular momentum conservation in heavy ion collisions at very high energy
• Global polarization of $\Lambda$ hyperons in Au+Au collisions at $\sqrt{s_{{}_{NN}}}$ = 200 GeV
• Global hyperon polarization at local thermodynamic equilibrium with vorticity, magnetic field and feed-down
• Rotating quark-gluon plasma in relativistic heavy ion collisions
• Vorticity in Heavy-Ion Collisions
• A study of vorticity formation in high energy nuclear collisions
• Global $\Lambda$ polarization in heavy-ion collisions from a transport model
• Vortical fluid and $\Lambda$ spin correlations in high-energy heavy-ion collisions
• Probing vorticity structure in heavy-ion collisions by local $\Lambda$ polarization
• Global polarization measurement in Au+Au collisions
• Lambda hyperon polarization in relativistic heavy ion collisions from the chiral kinetic approach
• Magnetic Field Induced Polarization Difference between Hyperons and Anti-hyperons
• Vorticity in low-energy heavy-ion collisions
• Hyperon polarization in Heavy-Ion Collisions and gravity-related anomaly
• Relaxation Time for Strange Quark Spin in Rotating Quark-Gluon Plasma
• $\Lambda$ polarization in peripheral collisions at moderate relativistic energies
• Axial anomaly and energy dependence of hyperon polarization in Heavy-Ion Collisions
• Vorticity and hyperon polarization at NICA energies
• Relaxation time for quark spin and thermal vorticity alignment in heavy-ion collisions
• Lambda polarization in heavy ion collisions: from RHIC BES to LHC energies
• Investigating different $\Lambda$ and $\bar{\Lambda }$ polarizations in relativistic heavy-ion collisions
• Fluid Dynamics Study of the $\Lambda$ Polarization for Au+Au Collisions at $\sqrt{s_{NN}}=200$ GeV
• Magnetic moment, vorticity-spin coupling and parity-odd conductivity of chiral fermions in 4-dimensional Wigner functions
• Vortical susceptibility of finite-density QCD matter
• Lambda Polarization in an Exact Rotating and Expanding fluid dynamical model for peripheral heavy ion reactions
• Polarization difference between hyperons and anti-hyperons induced by external magnetic field
• Local spin polarizations in relativistic heavy ion collisions

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• Relativistic second-order dissipative spin hydrodynamics from the method of moments
• Relativistic dissipative spin hydrodynamics from kinetic theory with a nonlocal collision term
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• Global spin polarization of multistrange hyperons and feed-down effect in heavy-ion collisions
• Resummed spin hydrodynamics from quantum kinetic theory
• Rise and fall of $\Lambda$ and $\bar{\Lambda }$ global polarization in semi-central heavy-ion collisions at HADES, NICA and RHIC energies from the core-corona model
• Fermion propagator in a rotating environment
• Anomalous gravitomagnetic moment and non-universality of the axial vortical effect at finite temperature
• Propagation of spin channel waves
• Mean free path of photons in relativistic heavy ion collisions
• Spin Polarization of $\Lambda$ hyperons from Dissipative Spin Hydrodynamics