Inhaltszusammenfassung

The elliptic flow of inclusive and direct photons was measured at mid-rapidity in two centrality classes 0-20% and 20-40% in Pb-Pb collisions at sNN‾‾‾‾√ =2.76 TeV by ALICE. Photons were detected with the highly segmented electromagnetic calorimeter PHOS and via conversions in the detector material with the e+e− pairs reconstructed in the central tracking system. The results of the two methods were combined and the direct photon elliptic flow was extracted in the transverse momentum range 0.9...The elliptic flow of inclusive and direct photons was measured at mid-rapidity in two centrality classes 0-20% and 20-40% in Pb-Pb collisions at sNN‾‾‾‾√ =2.76 TeV by ALICE. Photons were detected with the highly segmented electromagnetic calorimeter PHOS and via conversions in the detector material with the e+e− pairs reconstructed in the central tracking system. The results of the two methods were combined and the direct photon elliptic flow was extracted in the transverse momentum range 0.9<pT<6.2 GeV/c. We test the hypothesis vγ,dir2≡0 for 0.9<pT<2.1 GeV/c and obtain a significance of 1.4σ for the 0-20% class and 1.0σ for the 20-40% class. A comparison to RHIC data shows a similar magnitude of the measured elliptic flow, while hydrodynamic and transport model calculations predict a smaller flow than observed. » weiterlesen» einklappen

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DDC Sachgruppe:
Physik