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

20 May 2014, 16:30
spectrum (darmstadtium)



Board: C-17
Poster Initial State Physics Poster session


Risto Paatelainen (University of Jyväskylä)


Using next-to-leading order perturbative QCD and a conjecture of saturation to suppress the 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. In order to study higher cumulants $v_n$ and their event-by-event (EbyE) distributions, we are currently engaged in modeling the EbyE fluctuations of saturated minijet production in this framework [3]. Also these results will be reported. [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, **arXiv:1310.3105** [hep-ph], to appear in **Phys. Lett. B** [3] H. Niemi, K. J. Eskola, R. Paatelainen and K. Tuominen, work in progress

Primary authors

Harri Niemi (University of Jyväskylä) Kari J. Eskola (University of Jyvaskyla) Dr Kimmo Tuominen (University of Helsinki) Risto Paatelainen (University of Jyväskylä)

Presentation Materials