In this Letter we report the first results on pi(+/-), K-+/-, p, and (p) over bar production at midrapidity (vertical bar y vertical bar < 0.5) in central Pb-Pb collisions at root s(NN) = 2.76 TeV, measured by the ALICE experiment at the LHC. The p(T) distributions and yields are compared to previous results at root s(NN) = 200 GeV and expectations from hydrodynamic and thermal models. The spectral shapes indicate a strong increase of the radial flow velocity with root 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.

Pion, Kaon, and Proton Production in Central Pb-Pb Collisions at root s(NN)=2.76 TeV / B., A., J., A., D., A., A. M., A., M. M., A., G. A., R., A. G., A., A., A., S. A., S., Z., A., N., A., A. A., M., S. A., A., S. U., A., A., A., D., A., B., A., R. A., M., A., A., A., A., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - STAMPA. - 109:25(2012), pp. 252301-252301. [10.1103/physrevlett.109.252301]

Pion, Kaon, and Proton Production in Central Pb-Pb Collisions at root s(NN)=2.76 TeV

L. Cunqueiro;MEDDI, Franco;
2012

Abstract

In this Letter we report the first results on pi(+/-), K-+/-, p, and (p) over bar production at midrapidity (vertical bar y vertical bar < 0.5) in central Pb-Pb collisions at root s(NN) = 2.76 TeV, measured by the ALICE experiment at the LHC. The p(T) distributions and yields are compared to previous results at root s(NN) = 200 GeV and expectations from hydrodynamic and thermal models. The spectral shapes indicate a strong increase of the radial flow velocity with root 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.
2012
01 Pubblicazione su rivista::01a Articolo in rivista
Pion, Kaon, and Proton Production in Central Pb-Pb Collisions at root s(NN)=2.76 TeV / B., A., J., A., D., A., A. M., A., M. M., A., G. A., R., A. G., A., A., A., S. A., S., Z., A., N., A., A. A., M., S. A., A., S. U., A., A., A., D., A., B., A., R. A., M., A., A., A., A., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - STAMPA. - 109:25(2012), pp. 252301-252301. [10.1103/physrevlett.109.252301]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/552695
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