1202.2388 (J. Peralta-Ramos et al.)

Production of thermal photons in viscous fluid dynamics with
temperature-dependent shear viscosity    [PDF]

J. Peralta-Ramos, M. S. Nakwacki

We compute the spectrum of thermal photons created in Au+Au collisions at
$\sqrt{s_{NN}}=200$ 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 $\eta/s$. We find that the spectrum significantly depends on the values of
$\eta/s$ 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
$\eta/s$ 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.

View original: http://arxiv.org/abs/1202.2388