1303.0737 (ALICE Collaboration)

Centrality dependence of Pi, K, p production in Pb-Pb collisions at
sqrt(sNN) = 2.76 TeV    [PDF]

ALICE Collaboration

In this paper measurements are presented of Pi+, Pi-, K+, K-, p and antiproton production at mid-rapidity < 0.5, in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV as a function of centrality. The measurement covers the transverse momentum pt range from 100, 200, 300 MeV/c up to 3, 3, 4.6 GeV/c, for Pi, K, and p respectively. The measured pt distributions and yields are compared to expectations based on hydrodynamic, thermal and recombination models. The spectral shapes of central collisions show a stronger radial flow than measured at lower energies, which can be described in hydrodynamic models. In peripheral collisions, the pt distributions are not well reproduced by hydrodynamic models. Ratios of integrated particle yields are found to be nearly independent of centrality. The yield of protons normalized to pions is a factor ~1.5 lower than the expectation from thermal models.

View original: http://arxiv.org/abs/1303.0737