The inclusive transverse momentum (pT) distributions of primary charged particles are measured in the pseudo-rapidity range |η|<0.8 as a function of event centrality in Pb--Pb collisions at √sNN=2.76 TeV with ALICE at the LHC. The data are presented in the pT range 0.15<pT<50 GeV/c for nine centrality intervals from 70--80% to 0--5%. The Pb-Pb spectra are presented in terms of the nuclear modification factor RAA using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-pT particles strongly depends on event centrality. In central collisions (0-5%) the yield is most suppressed with RAA≈0.13 at pT=6-7 GeV/c. Above pT=7 GeV/c, there is a significant rise in the nuclear modification factor, which reaches RAA≈0.4 for pT>30 GeV/c. In peripheral collisions (70-80%), the suppression is weaker with RAA≈0.7 almost independently of pT. The measured nuclear modification factors are compared to other measurements and model calculations.
Centrality dependence of charged particle production at large transverse momentum in Pb–Pb collisions at √sNN =2.76 TeV
BREGANT, MARCO;CAMERINI, Paolo;CONTIN, GIACOMO;FRAGIACOMO, ENRICO;GROSSO, Raffaele;LEA, RAMONA;MARGAGLIOTTI, GIACOMO;RUI, RINALDO;VENARUZZO, MASSIMO;V. Zaccolo;
2013-01-01
Abstract
The inclusive transverse momentum (pT) distributions of primary charged particles are measured in the pseudo-rapidity range |η|<0.8 as a function of event centrality in Pb--Pb collisions at √sNN=2.76 TeV with ALICE at the LHC. The data are presented in the pT range 0.15Pubblicazioni consigliate
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