Azimuthal anisotropy of charged particles at high transverse momenta in Pb-Pb collisions at sqrt[s(NN)] = 2.76  TeV.

The azimuthal anisotropy of charged particles in Pb-Pb collisions at sqrt[s(NN)]=2.76  TeV is measured with the CMS detector at the LHC over an extended transverse momentum (p(T)) range up to approximately 60  GeV/c. The data cover both the low-p(T) region associated with hydrodynamic flow phenomena...

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Bibliographic Details
Main Authors: Chatrchyan, S, Khachatryan, V, Sirunyan, A, Tumasyan, A, Adam, W, Bergauer, T, Dragicevic, M, Erö, J, Fabjan, C, Friedl, M, Frühwirth, R, Ghete, V, Hammer, J, Hörmann, N, Hrubec, J, Jeitler, M, Kiesenhofer, W, Krammer, M, Liko, D, Mikulec, I, Pernicka, M, Rahbaran, B, Rohringer, C, Rohringer, H, Schöfbeck, R
Format: Journal article
Language:English
Published: 2012
Description
Summary:The azimuthal anisotropy of charged particles in Pb-Pb collisions at sqrt[s(NN)]=2.76  TeV is measured with the CMS detector at the LHC over an extended transverse momentum (p(T)) range up to approximately 60  GeV/c. The data cover both the low-p(T) region associated with hydrodynamic flow phenomena and the high-p(T) region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with p(T), reaching a maximum around p(T)=3  GeV/c, and then to gradually decrease to almost zero, with the decline persisting up to at least pp(T)=40  GeV/c over the full centrality range measured.