Hyperon--anti-hyperon polarization asymmetry in relativistic heavy-ion collisions as an interplay between chiral and helical vortical effects

Abstract

We argue that the enhancement in the spin polarization of anti-hyperons compared to the polarization of the hyperons in noncentral relativistic heavy-ion collisions arises as a result of an interplay between the chiral and helical vortical effects. The chiral vortical effect generates the axial current of quarks along the vorticity axis while the recently found helical vortical effect generates the helicity flow -- the projection of the quark's polarization vector onto its momentum -- along the same axis. For massless fermions, the helical charge corresponds to a difference in the contributions of particles and anti-particles to the axial charge. Assuming that the spin of light quarks transfers to the strange quarks via the vector kaon states ("the spin-vector dominance"), we are able to describe the ratio of the (anti)hyperon spin polarizations, obtained by the STAR group, without fitting parameters. We also argue that the helical vortical effect dominates over the chiral vortical effect and the chiral magnetic effect in the generation of the electric current.

arXiv comment9 pages, 3 figures; v2: discussions expanded, chiral magnetic effect and helical vortical effect are compared

References in corpus (39)

• Collective flow and viscosity in relativistic heavy-ion collisions
• New Forms of QCD Matter Discovered at RHIC
• Viscosity Information from Relativistic Nuclear Collisions: How Perfect is the Fluid Observed at RHIC?
• Hydrodynamics with Triangle Anomalies
• Global $\Lambda$ hyperon polarization in nuclear collisions: evidence for the most vortical fluid
• Chiral Magnetic and Vortical Effects in High-Energy Nuclear Collisions --- A Status Report
• What RHIC Experiments and Theory tell us about Properties of Quark-Gluon Plasma ?
• Elliptic flow in Au+Au collisions at sqrt(s_NN) = 130 GeV
• Comparison of Chemical Freeze-Out Criteria in Heavy-Ion Collisions
• Globally Polarized Quark-gluon Plasma in Non-central A+A Collisions
• Global polarization of $\Lambda$ hyperons in Au+Au collisions at $\sqrt{s_{{}_{NN}}}$ = 200 GeV
• New theories of relativistic hydrodynamics in the LHC era
• Comments About the Electromagnetic Field in Heavy-Ion Collisions
• Hydrodynamics Beyond the Gradient Expansion: Resurgence and Resummation
• Early thermalization at RHIC
• Global hyperon polarization at local thermodynamic equilibrium with vorticity, magnetic field and feed-down
• Hydrodynamics of R-charged black holes
• Polarization of $\Lambda$ ($\bar{\Lambda }$) hyperons along the beam direction in Au+Au collisions at $\sqrt{s_{{}_{NN}}}$ = 200 GeV
• Shear-induced spin polarization in heavy-ion collisions
• Spin-thermal shear coupling in a relativistic fluid
• Relativistic dissipative spin dynamics in the relaxation time approximation
• Global polarization of $\Lambda$ and $\overline{\Lambda }$ hyperons in Pb-Pb collisions at the LHC
• Magnetic Field Induced Polarization Difference between Hyperons and Anti-hyperons
• Helicity separation in Heavy-Ion Collisions
• Diffusion of conserved charges in relativistic heavy ion collisions
• Hyperon polarization in Heavy-Ion Collisions and gravity-related anomaly
• Different space-time freeze-out picture -- an explanation of different $\Lambda$ and $\bar{\Lambda }$ polarization?
• $\Lambda$ and $\bar{\Lambda }$ spin interaction with meson fields generated by the baryon current in high energy nuclear collisions
• Relaxation Time for Strange Quark Spin in Rotating Quark-Gluon Plasma
• Axial anomaly and energy dependence of hyperon polarization in Heavy-Ion Collisions
• Spin Hydrodynamic Generation in the Charged Subatomic Swirl
• Temperature dependence of the axial magnetic effect in two-color quenched QCD
• Numerical evidence of the axial magnetic effect
• Strange hadron production in heavy ion collisions from SPS to RHIC
• Is Hyperon Polarization in Relativistic Heavy Ion Collisions Connected to Axial U(1) Symmetry Breaking at High Temperature?
• Strangeness Neutrality and QCD Thermodynamics
• A lattice study of the spin structure of the Lambda hyperon
• Helical massive fermions under rotation
• Vortical effects in Dirac fluids with vector, chiral and helical charges

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• Chiral hydrodynamics in strong external magnetic fields
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• $\Lambda /\bar{\Lambda }$ Polarization and Splitting Induced by Rotation and Magnetic Field
• Hydrodynamic helicity polarization in relativistic heavy ion collisions
• Relativistic hydrodynamics with spin in the presence of electromagnetic fields
• Spin waves in spin hydrodynamics
• Anomalous magnetohydrodynamics with temperature-dependent electric conductivity and application to the global polarization
• Spin polarization induced by magnetic field and the relativistic Barnett effect
• Fast kinetic simulator for relativistic matter
• Shear-induced anomalous transport and charge asymmetry of triangular flow in heavy-ion collisions
• Vortical waves in a quantum fluid with vector, axial, and helical charges. I. Non-dissipative transport
• Helical Separation Effect and helical heat transport for Dirac fermions
• Polarization Dynamics in Paramagnet of Charged Quark-Gluon Plasma
• Vortical waves in a quantum fluid with vector, axial and helical charges. II. Dissipative effects