# XIIIth Quark Confinement and the Hadron Spectrum

31 July 2018 to 6 August 2018
Maynooth University
Europe/Dublin timezone

## Nonequilibrium viscous correction to the phase space density and bulk viscosity in the relaxation time approximation

3 Aug 2018, 14:30
30m
Hall F (Arts Bldg.)

### Hall F

#### Arts Bldg.

Talk D: Deconfinement

### Speaker

Alina Czajka (McGill University/Jan Kochanowski University)

### Description

We present the correct form of the nonequilibrium viscous correction to the phase space density in the relaxation time approximation that properly takes into account the space-time dependence of the thermal mass. We also investigate the impact the correction has on the bulk viscosity. This correction automatically satisfies the Landau matching condition and energy-momentum conservation. It also makes the appearance of the Callan-Symanzyk $\beta_\lambda$-function natural in the bulk viscosity calculation. The bulk viscosity has the expected parametric form for the Boltzmann gas, while for the Bose-Einstein case, it is affected by the cut-off of infrared divergences. This may be an indication that the relaxation time approximation is too crude to obtain the correct form of the bulk viscosity for quantum gases.

### Primary author

Alina Czajka (McGill University/Jan Kochanowski University)

### Co-authors

Sigtryggur Hauksson (McGill University) Dr Chun Shen (Brookhaven National Laboratory) Sangyong Jeon (McGill University) Prof. Charles Gale (McGill University)