Spectra and elliptic flow for identified hadrons in 2.76 A TeV Pb+Pb collisions

Abstract

Using the VISHNU hybrid model that couples (2+1)-dimensional viscous hydrodynamics to a microscopic hadronic transport model, we calculate the multiplicity, p_T spectra and elliptic flow for pions, kaons, and protons in 2.76 A TeV Pb+Pb collisions, using MC-KLN initializations with smoothed initial conditions, obtained by averaging over a large number of events. The results from our calculations are compared to data from the ALICE collaboration, showing nice agreement over several centrality bins. Using the same inputs, we predict the p_T spectra and elliptic flow for phi mesons and explore its flow development in the strong and weak coupling limits through hydrodynamic calculations with different decoupling temperatures. In addition we study the influence of baryon and anti-baryon annihilation processes on common observables and demonstrate that by including annihilation processes below a switching temperature of 165 MeV, VISHNU provides a good description of the multiplicity and p_T spectra for pions, kaons and protons measured by PHENIX and ALICE at both RHIC and the LHC.