Direct photon production in pp, p–Pb and Pb–Pb collisions measured with the ALICE experiment
NRC “Kurchatov institute”
* e-mail: Dmitri.Peresunko@cern.ch
Published online: 31 October 2018
We review recent ALICE results on direct photon production in pp, p–Pb and Pb–Pb collisions at LHC energies. In light systems, pp and p–Pb, no signal of direct photons at low pT < 3-5 GeV/c is observed within uncertainties, while at high pT our measurements are consistent with NLO pQCD calculations. In central and mid-central Pb–Pb collisions a thermal photon contribution is observed at low pT < 3 - 4 GeV/c with slopes Teff = (304 ± 11stat ± 40syst) MeV and (407 ± 61stat ± 96syst) MeV respectively. A collective elliptic flow of direct photons is measured and appeared to be close to the decay photon flow.
© The Authors, published by EDP Sciences, 2018
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.