Production of thermal photons in viscous fluid dynamics with temperature-dependent shear viscosity
Abstract
We compute the spectrum of thermal photons created in Au+Au collisions at
s
NN
−
−
−
−
√
=200
GeV, taking into account dissipative corrections in production processes corresponding to the quark--gluon plasma and hadronic phases. To describe the evolution of the fireball we use a viscous fluid dynamic model with different parametrizations for the temperature--dependence of
η/s
. We find that the spectrum significantly depends on the values of
η/s
in the QGP phase, and is almost insensitive to the values in the hadronic phase. We also compare the influence of the temperature--dependence of
η/s
on the spectrum of thermal photons to that of using different equations of state in the fluid dynamic simulations, finding that both effects are of the same order of magnitude.