Probing Rotational Dynamics of Quark Gluon Plasma via Global Vorticity

Abstract

The findings on the spin polarization of $\Lambda$, $\Xi$, and $\Omega$ hyperons and spin alignment of $K^{\ast 0}$, $\varphi$, and $D^{\ast +}$ mesons in relativistic heavy-ion collision experiments at the RHIC and LHC facilities propose the emergence of a strong vorticity field produced in these collisions. Contemplating the potential impact of vorticity on the space-time evolution of deconfined QCD matter and its freeze-out properties, we aim to investigate its characteristics within the medium. We introduce a complementary and data-driven approach to quantify the global vorticity field by extracting it directly from the transverse momentum spectra of produced hadrons. Employing the experimental data for $\Lambda$, $\Xi$, $\Omega$, $K^{\ast 0}$, $K^{\ast \pm }$, $\varphi$, $\rho$, and $D^{\ast +}$ at mid-rapidity in Au+Au and Pb+Pb collisions over a wide range of beam energies, $\sqrt{s_{\mathrm{NN}}}=7.7$ GeV-5.02 TeV, and centrality classes, we systematically examine spin-vorticity coupling in the medium. Our finding on the magnitude of the extracted vorticity is consistent with values deduced from $\Lambda$ and $\bar{\Lambda }$ polarization measurements using statistical thermal models under the non-relativistic limit. Notably, we observe a prominent particle-species dependence of the vorticity, as well as a non-trivial variation with collision centrality and beam energy. These results indicate that vorticity-driven spin phenomena are sensitive to hadron structure and freeze-out dynamics, providing new constraints on the rotational properties of the QCD matter.

Same as the published version in Phys. Letts. B. For supplementary materials, please see the online link using the journal DOI

References in corpus (11)

• K*(892)${}^0$ and $\Phi$(1020) production in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV
• Polarization probes of vorticity in heavy ion collisions
• Collective longitudinal polarization in relativistic heavy-ion collisions at very high energy
• Pattern of Global Spin Alignment of $\varphi$ and $K^{\ast 0}$ mesons in Heavy-Ion Collisions
• A hydrodynamic study of hyperon spin polarization in relativistic heavy ion collisions
• Velocity and Vorticity Measurements of Jupiter's Great Red Spot Using Automated Cloud Feature Tracking
• Hyperon polarization and its relation with directed flow in high-energy nuclear collisions
• Impact of vorticity and viscosity on the hydrodynamic evolution of hot QCD medium
• Thermodynamics of a rotating hadron resonance gas with van der Waals interaction
• Effect of Coriolis force on the shear viscosity of quark matter: A nonrelativistic description
• Impact of strong magnetic field, baryon chemical potential, and medium anisotropy on polarization and spin alignment of hadrons