(NISER-TIFR discussion session) Utsab Gangopadhyay

Title: Transport coefficients of a Hot Hadronic Matter\\

Abstract: The work deals with the study of transport properties of the later stage of
a heavy ion collision, mainly after chemical freeze-out, from a kinetic theory approach.
Transport coefficients that appear in second-order hydrodynamics for pion gas has
been calculated using the relativistic form of the Grads 14-moment method. Instead of
using the relativistic generalization developed by Israel-Stewart we have used Denicol-
Neime-Molnar-Rischke theory. The transport coefficients like bulk viscosity, shear
viscosity and thermal conductivity that goes in as input to calculate the relaxation time
of flows that appear in the second-order hydrodynamic theory has been calculated
using the Chapman-Enskog method.
Transport coefficients in first-order hydrodynamics like shear viscosity, bulk viscosity,
thermal conductivity, Dufour coefficient, thermal diffusion coefficient and diffusion
coefficient for a mixture of pions and nucleons have been investigated, for a finite
baryonic chemical potential. These cross-sections which appear in the collision
integral is the dynamic input; through these cross-sections, the interaction between
the constituent particles are introduced. But for a more realistic picture we have
incorporated medium-effect in our cross-section, as the system we are studying
presumably, is at a high temperature and density. The effect of a thermal medium is
quantified through the self-energy of the propagators in ππ and πN collisions, which at
finite temperature is evaluated using the real time formalism of thermal field theory