Details

Autor(en) / Beteiligte

• Al-Turany, M.
• Alt, T.
• Andrei, C.
• Apadula, N.
• Bailhache, R.
• Bartsch, E.
• Baruffaldi, F.
• Bastid, N.
• Bhasin, A.
• Bianchi, N.
• Biswas, S.
• Bluhme, N.
• Blume, C.
• Bodova, T.
• Boldizsár, L.
• Borissov, A.
• Bratrud, L.
• Braun-Munzinger, P.
• Bregant, M.
• Buthelezi, Z.
• Bylinkin, A.
• Caliva, A.
• Camacho, J. M. M.
• Chakaberia, I.
• Concas, M.
• Conesa Balbastre, G.
• Contreras, J. G.
• Dainese, A.
• Danu, A.
• Del Grande, R.
• Eisenhut, F.
• Evans, D.
• Faggin, M.
• Faivre, J.
• Fecchio, P.
• Gaardhøje, J. J.
• Gal, A.
• Gianotti, P.
• Gotovac, S.
• Greiner, L.
• Grigoras, C.
• Grigoriev, V.
• Harris, J. W.
• Iddon, J. P.
• Isakov, A.
• Jung, J.
• Jung, M.
• Jusko, A.
• Kaplin, V.
• Kashyap, V.
• Keijdener, D. L. D.
• Khatun, A.
• Kileng, B.
• Kim, B.
• Kim, M.
• Kiselev, S.
• Laudi, E.
• Malaev, M.
• Manzari, V.
• Margagliotti, G. V.
• Massacrier, L.
• Mazzaschi, F.
• Modak, A.
• Mulligan, J. D.
• Negru, A.
• Nesbo, S. V.
• Neskovic, G.
• Nesterov, D.
• Ogino, M.
• Oppedisano, C.
• Paul, B.
• Pinsky, L.
• Pinto, C.
• Pop, A.
• Ramello, L.
• Riegler, W.
• Rybicki, A.
• Saetre, J.
• Sahoo, B.
• Sahu, D.
• Sarkar, D.
• Schweda, K.
• Shangaraev, A.
• Shigaki, K.
• Shirinkin, S.
• Slupecki, M.
• Soncco, C.
• Tersimonov, G.
• Tieulent, R.
• Timmins, A. R.
• Torales-Acosta, F.
• Trifiró, A.
• Turrisi, R.
• Ullaland, K.
• Vasiliev, A.
• Verweij, M.
• Yoo, I.-K.
• Zampolli, C.
• Zanoli, H. J. C.
• Zherebchevskii, V.

Titel

Dielectron production at midrapidity at low transverse momentum in peripheral and semi-peripheral Pb–Pb collisions at sNN = 5.02 TeV

Ist Teil von

• The journal of high energy physics, 2023-06, Vol.2023 (6), p.24

Ort / Verlag

Berlin/Heidelberg: Springer Berlin Heidelberg

Erscheinungsjahr

2023

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• A bstract The first measurement of the e + e − pair production at low lepton pair transverse momentum ( p T , ee ) and low invariant mass ( m ee ) in non-central Pb–Pb collisions at s NN = 5 . 02 TeV at the LHC is presented. The dielectron production is studied with the ALICE detector at midrapidity ( |η e | < 0 . 8) as a function of invariant mass (0.4 ≤ m ee < 2 . 7 GeV/ c 2 ) in the 50–70% and 70–90% centrality classes for p T , ee < 0.1 GeV/ c , and as a function of p T , ee in three m ee intervals in the most peripheral Pb–Pb collisions. Below a p T , ee of 0.1 GeV/ c , a clear excess of e + e − pairs is found compared to the expectations from known hadronic sources and predictions of thermal radiation from the medium. The m ee excess spectra are reproduced, within uncertainties, by different predictions of the photon–photon production of dielectrons, where the photons originate from the extremely strong electromagnetic fields generated by the highly Lorentz-contracted Pb nuclei. Lowest-order quantum electrodynamic (QED) calculations, as well as a model that takes into account the impact-parameter dependence of the average transverse momentum of the photons, also provide a good description of the p T , ee spectra. The measured p T , ee 2 of the excess p T , ee spectrum in peripheral Pb–Pb collisions is found to be comparable to the values observed previously at RHIC in a similar phase-space region.