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.

B. Abelev, J. Adam, D. Adamová, A. Adare, M. Aggarwal, G. Aglieri Rinella, et al. (2012). Pion, Kaon, and Proton Production in Central Pb-Pb Collisions at sqrt[s_{NN}]=2.76  TeV. PHYSICAL REVIEW LETTERS, 109, 1-11 [10.1103/PhysRevLett.109.252301].

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

AGOSTINELLI, ANDREA;A. Alici;ARCELLI, SILVIA;BASILE, MAURIZIO;BELLINI, FRANCESCA;CIFARELLI, LUISA;GUERZONI, BARBARA;SCIOLI, GILDA;
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
B. Abelev, J. Adam, D. Adamová, A. Adare, M. Aggarwal, G. Aglieri Rinella, et al. (2012). Pion, Kaon, and Proton Production in Central Pb-Pb Collisions at sqrt[s_{NN}]=2.76  TeV. PHYSICAL REVIEW LETTERS, 109, 1-11 [10.1103/PhysRevLett.109.252301].
B. Abelev;J. Adam;D. Adamová;A. Adare;M. Aggarwal;G. Aglieri Rinella;A. Agocs;A. Agostinelli;S. Aguilar Salazar;Z. Ahammed;N. Ahmad;A. Ahmad Masoodi;S...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/142604
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