Title:
Determining QCD matter viscosity from fluid dynamics with saturated minijet 
initial conditions in ultrarelativistic A+A collisions

Authors:
R. Paatelainen (speaker), K.J Eskola, H. Niemi and K. Tuominen

Abstract:
Using next-to-leading order perturbative QCD and a conjecture of saturation to suppress
production of low energy quanta, we calculate the initial energy densities and formation 
times for the dissipative fluid dynamical evolution of the quark-gluon plasma produced 
in ultrarelativistic heavy ion collisions [1,2]. We identify the uncertainties of the 
model and demonstrate the predictive power of the approach by obtaining a good global 
agreement with the measured centrality dependence of the charged particle multiplicities, 
transverse momentum spectra and elliptic flow simultaneously for the Pb+Pb collisions at 
the LHC and Au+Au at RHIC. In particular, the shear viscosity-to-entropy ratio in the
different phases of QCD matter is simultaneously constrained by all these data.

[1] R. Paatelainen, K.J Eskola, H. Holopainen and K. Tuominen, Phys. Rev. C87 (2012) 044904
[2] R. Paatelainen, K.J Eskola, H. Niemi and K. Tuominen, work in progress