E-resources
PDF-
Bagnasco, S.; Barbano, A.M.; Batyunya, B.; Belmont, R.; Bertens, R.A.; Berzano, D.; Bhasin, A.; Broker, T.A.; Bufalino, S.; Chojnacki, M.; Christiansen, P.; Cormier, T.M.; Dahms, T.; Divià, R.; Dobrin, A.; Evans, D.; Fantoni, A.; Festanti, A.; Filchagin, S.; Foertsch, S.; Fragiacomo, E.; Gago, A.M.; Garabatos, C.; Grigoras, C.; Grigoryan, S.; Gupta, R.; Hadjidakis, C.; Hamar, G.; Hosokawa, R.; Huang, M.; Hussain, N.; Inaba, M.; Jacobs, P.M.; Jadlovska, S.; Kamin, J.; Karavicheva, T.; Kim, D.J.; Kim, M.; Kim, M.; Kirsch, S.; Klein, C.; Knichel, M.L.; Kondratiev, V.; Kondratyuk, E.; Krzewicki, M.; Kumar, J.; Kumar, S.; Li, X.; López Torres, E.; Luettig, P.; Malaev, M.; Masoni, A.; Mazer, J.; Mcdonald, D.; Meninno, E.; Moreira De Godoy, D.A.; Musinsky, J.; Nandi, B.K.; Onderwaater, J.; Ortiz Velasquez, A.; Oyama, K.; Ozdemir, M.; Papcun, P.; Papikyan, V.; Pappalardo, G.S.; Passfeld, A.; Peresunko, D.; Poghosyan, M.G.; Polichtchouk, B.; Porteboeuf-Houssais, S.; Pruneau, C.A.; Pujahari, P.; Redlich, K.; Reichelt, P.; Romita, R.; Ronflette, L.; Roukoutakis, F.; Ryabinkin, E.; Schukraft, J.; Sekiguchi, Y.; Sevcenco, A.; Sibiriak, Y.; Song, M.; Spiriti, E.; Steyn, G.; Takahashi, J.; Tarzila, M.G.; Uras, A.; Usai, G.L.; Vallero, S.; Vinogradov, L.; Virgili, T.; Wang, H.; Wikne, J.; Wilkinson, J.; Zhang, X.; Zhou, Z.; Zhu, H.; Zhu, J.; Zinovjev, G.
Physics letters. B, 03/2016, Volume: 754, Issue: CJournal Article
Direct photon production at mid-rapidity in Pb–Pb collisions at sNN=2.76 TeV was studied in the transverse momentum range 0.9<pT<14 GeV/c. Photons were detected with the highly segmented electromagnetic calorimeter PHOS and via conversions in the ALICE detector material with the e+e− pair reconstructed in the central tracking system. The results of the two methods were combined and direct photon spectra were measured for the 0–20%, 20–40%, and 40–80% centrality classes. For all three classes, agreement was found with perturbative QCD calculations for pT≳5 GeV/c. Direct photon spectra down to pT≈1 GeV/c could be extracted for the 20–40% and 0–20% centrality classes. The significance of the direct photon signal for 0.9<pT<2.1 GeV/c is 2.6σ for the 0–20% class. The spectrum in this pT range and centrality class can be described by an exponential with an inverse slope parameter of (297±12stat±41syst) MeV. State-of-the-art models for photon production in heavy-ion collisions agree with the data within uncertainties.
