# Pion, Kaon, and Proton Production in Central Pb--Pb Collisions at $\sqrt{s_{NN}} = 2.76$ TeV

Abstract : In this Letter we report the first results on $\pi^\pm$, K$^\pm$, p and pbar production at mid-rapidity (|y|<0.5) in central Pb-Pb collisions at sqrt{s_{NN}} = 2.76 TeV, measured by the ALICE experiment at the LHC. The pT distributions and yields are compared to previous results at sqrt{s_{NN}} = 200 GeV and expectations from hydrodynamic and thermal models. The spectral shapes indicate a strong increase of the radial flow velocity with sqrt{s_{NN}}, which in hydrodynamic models is expected as a consequence of the increasing particle density. While the K/pi ratio is in line with predictions from the thermal model, the p/pi ratio is found to be lower by a factor of about 1.5. This deviation from thermal model expectations is still to be understood.
Document type :
Journal articles
Domain :

http://hal.in2p3.fr/in2p3-00723478
Contributor : Emmanuelle Vernay <>
Submitted on : Friday, August 10, 2012 - 9:12:19 AM
Last modification on : Monday, July 20, 2020 - 9:18:25 AM

### Citation

B. Abelev, N. Arbor, G. Conesa Balbastre, J. Faivre, C. Furget, et al.. Pion, Kaon, and Proton Production in Central Pb--Pb Collisions at $\sqrt{s_{NN}} = 2.76$ TeV. Physical Review Letters, American Physical Society, 2012, 109, pp.252301. ⟨10.1103/PhysRevLett.109.252301⟩. ⟨in2p3-00723478⟩

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