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22-27 March 2015
Hotel do Bosque
Brazil/East timezone

Prompt photon measurements with ALICE experiment for quark-gluon plasma study

26 Mar 2015, 17:30
Hotel do Bosque

Hotel do Bosque

Rodovia Mário Covas (Rio-Santos) BR - 101 Sul, Km 533, Angra dos Reis, RJ, Brazil
Oral presentation Relativistic heavy-ion reactions - new data, analyses and models Relativistic heavy-ion reactions - new data, analyses and models


Dr Alexis Jean-Michel Mas (Universidade de Sao Paulo (BR))


The ALICE experiment is mainly devoted to the study of quark-gluon plasma (QGP) expected to be created in heavy ion collisions. Since electromagnetic probes do not interact strongly whith the QGP, direct photons are reliable witnesses of the energy of the initial hard process. This property allows one to investigate, e.g., hadrons energy loss mechanisms in the medium via gammajet studies. The measurement of direct photons production is also interesting in p-p collisions, as it provides a test of the QCD cross section as well as it constrains the proton parton distribution function (PDF). The ALICE Electromagnetic Calorimeter (EMCal) efficiently detects photons up to pt=100 GeV/c. To identify direct photons, a combination of techniques including (electromagnetic) shower shape analysis and isolation cut has been used. These methods are efficient in getting rid of decay photons background, dominant in p-p collision at the TeV energy scale. An overview of ALICE prompt photon measurements in pp and Pb-Pb collisions will be presented. Finally the complementarity of ALICE and the other experiments (CMS and ATLAS) will be highlighted.

Primary author

Dr Alexis Jean-Michel Mas (Universidade de Sao Paulo (BR))

Presentation Materials