Hydrodynamical analysis of centrality dependence of charged particle's multiplicity in ${\sqrt{s}}_{NN}$=2.76 TeV Pb+Pb collisions

Abstract

In Israel-Stewart's theory of dissipative hydrodynamics, we have analyzed the recent ALICE data for the centrality dependence of charged particle multiplicity, centrality dependence of integrated elliptic flow and 0-5% charged particles $p_T$ spectra in ${\sqrt{s}}_{NN}$=2.76 TeV Pb+Pb collisions and determined the initial or the thermalisation time. Analysis indicate that the ALICE data disfavor very early thermalsiation ${\tau }_i$=0.2 fm, or very late thermalsation ${\tau }_i$= 4fm. Data are best explained for thermalisation time ${\tau }_i=0.88_{+0.68}^{-0.14}$ fm.

Comments: Final version published in Phys. Rev. C. 4 pages, 3 figures