2025/12/21 by Bhagyarathi Sahoo, Captain R. Singh, Sahoo, Bhagyarathi +3
Physics and Astronomy · #Dust and Plasma Wave Phenomena #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #High-Energy Particle Collisions Research #Nuclear Experiment (nucl-ex) #Nuclear Theory (nucl-th) #Quantum Chromodynamics and Particle Interactions
paper · doi:10.48550/arxiv.2512.18728
openalex publication_date 2025/12/21 · openalex created_date 2025/12/24 · openalex updated_date 2026/07/28
The observation of spin alignment of quarkonia in ultra-relativistic heavy-ion collisions provides deep insight into the possible formation of the quark-gluon plasma (QGP). The present study investigates the spin alignment of quarkonia induced by dissociation mechanisms arising from medium effects imposed on quarkonia. We implement an effective Hamiltonian with a medium-modified color-singlet potential to incorporate the coupling of quarkonium spin with medium vorticity. This coupling gives rise to spin-dependent dissociation, which we identify as a plausible mechanism contributing to quarkonium spin alignment. Within the ambit of second-order relativistic viscous hydrodynamics, we calculate the spin-dependent decay widths of charmonium (J/ψ, ψ(2S)) and bottomonium (Υ(1S), Υ(2S)) in a rotating thermal medium, including collisional damping and gluonic dissociation effects. We evaluate the observable ρ00 for Pb--Pb collisions at √s\rm NN = 5.02 TeV as a function of transverse momentum of the quarkonia, charged particle multiplicity, and medium rotation. The results demonstrate that medium vorticity modifies the quarkonia net decay width and, as a consequence, quarkonia spin alignment gets modified. These findings suggest new directions for understanding spin transport and the microscopic dynamics of vortical QGP.