Relativistic dissipative hydrodynamics with momentum-dependent relaxation time: Magnetic field effects and quarkonia phenomenology.

by Mr Sunny Kumar Singh (IIT, Gandhinagar)

Thursday 23 Oct 2025, 14:30 → 15:30 Asia/Kolkata

A304

The study of the quark–gluon plasma (QGP), a deconfined state of strongly interacting matter created in relativistic heavy-ion collisions, requires a consistent relativistic dissipative hydrodynamic framework to describe its space–time evolution. In this talk, I will present a derivation of the hydrodynamic evolution equations from kinetic theory using a Chapman–Enskog–like expansion within the Extended Relaxation Time Approximation (ERTA), which introduces a momentum-dependent relaxation time in place of the momentum-independent one used in traditional RTA approaches. The resulting evolution equations for the particle number current and shear stress tensor yield transport coefficients that agree with first-principle results for a massless scalar theory with $\lambda \phi^4$ interaction. The formalism was further extended to include the effects of external electromagnetic fields, and the gluon self-energy and screening mass are computed within the one-loop Hard Thermal Loop (HTL) framework incorporating the non-equilibrium corrections. Using these inputs, we evaluated the real and imaginary parts of the quarkonia potential and extracted the corresponding binding energies and thermal widths, highlighting the significant influence of momentum-dependent relaxation dynamics on quarkonia dissociation and related transport phenomena.