Temperature dependence of the QGP viscosity over entropy ratio from hydrodynamical analysis of ALICE data in $\sqrt{s_{NN}}$?= 2.76 TeV Pb?+?Pb collisions
Within Israel?Stewart's theory of dissipative hydrodynamics, we have analyzed ALICE data for the centrality dependence of charged particle multiplicity, elliptic flow and pT spectra in ?= 2.76 TeV Pb?+?Pb collisions and obtained the temperature dependence of the QGP viscosity over the entropy ratio . If temperature dependence of is parameterized as , experimental data favor ? in the range 0?0.2. ? ? 0.4 is not favored by the data. Experimental data in ?= 200?GeV Au + Au collisions however, prefer ??= 0.4.