https://doi.org/10.1140/epja/i2014-14063-4
Regular Article - Theoretical Physics
Shear viscosity from Kubo formalism: NJL model study
1
Physik Department, Technische Universität München, D-85747, Garching, Germany
2
Theoretical Research Division, Nishina Center, RIKEN, 351-0198, Wako, Japan
3
ECT*, Villa Tambosi, I-38123, Villazzano (TN), Italy
* e-mail: robert.lang@ph.tum.de
Received:
19
November
2013
Revised:
7
February
2014
Accepted:
22
February
2014
Published online:
26
March
2014
A large-N c expansion is combined with the Kubo formalism to study the shear viscosity η of strongly interacting matter in the two-flavor NJL model. We discuss analytical and numerical approaches to η and investigate systematically its strong dependence on the spectral width and the momentum-space cutoff. Thermal effects on the constituent quark mass from spontaneous chiral symmetry breaking are included. The ratio η/s and its thermal dependence are derived for different parameterizations of the spectral width and for an explicit one-loop calculation including mesonic modes within the NJL model.
© SIF, Springer-Verlag Berlin Heidelberg, 2014