Measurement of dielectron production in central Pb-Pb collisions at √sNN=2.76 TeV
Acharya, Shreyasi; Acosta, Fernando Torales; Adamová, Dagmar; Adolfsson, Jonatan; Aggarwal, Madan M.; Aglieri Rinella, Gianluca; Agnello, Michelangelo; Agrawal, Nikita; Ahammed, Zubayer; Ahn, Sang Un; Alme, Johan; Altenkaemper, Lucas; Djuvsland, Øystein; Ersdal, Magnus Rentsch; Fionda, Fiorella Maria Celeste; Nystrand, Joakim; Rehman, Attiq ur; Røhrich, Dieter; Tambave, Ganesh Jagannath; Ullaland, Kjetil; Wagner, Boris; Zhou, Zhuo; Arsene, Ionut Cristian; Bätzing, Paul Christoph; Dordic, Olja; Lardeux, Antoine Xavier; Lindal, Svein; Mahmood, Sohail Musa; Malik, Qasim Waheed; Richter, Matthias; Røed, Ketil; Skaali, Toralf Bernhard; Tveter, Trine Spedstad; Wikne, Jon Christopher; Zhao, Chengxin; Helstrup, Håvard; Hetland, Kristin Fanebust; Kileng, Bjarte; Nesbø, Simon Voigt; Storetvedt, Maksim Melnik; Langøy, Rune; Lien, Jørgen André; Aiola, Salvatore; Akindinov, Alexander; Al-Turany, Mohammed; Alam, Sk Noor; De Albuquerque, Danilo Silva; Aleksandrov, Dimitry; Alessandro, Bruno; Alfaro Molina, José Rubén; ALICE, Collaboration
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2019Metadata
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Acharya, S., Acosta, F. T., Adamová, D., Adolfsson, J., Aggarwal, M. M., Aglieri Rinella, G., . . . Zou, S. (2019). Measurement of dielectron production in central Pb-Pb collisions at √sNN=2.76TeV. Physical Review C, 99(2). 10.1103/PhysRevC.99.024002Abstract
The first measurement of dielectron (e+e−) production in central (0–10%) Pb–Pb collisions at √sNN =2.76 TeV at the LHC is presented. The dielectron invariant-mass spectrum is compared to the expectedcontributions from hadron decays in the invariant-mass range 0 < mee < 3.5 GeV/c2. The ratio of dataand the cocktail of hadronic contributions without vacuum ρ0 is measured in the invariant-mass range0.15 < mee < 0.7 GeV/c2, where an excess of dielectrons is observed in other experiments, and its value is1.40 ± 0.28 (stat.) ± 0.08 (syst.) ± 0.27 (cocktail). The dielectron spectrum measured in the invariant massrange 0 < mee < 1 GeV/c2 is consistent with the predictions from two theoretical model calculations thatinclude thermal dielectron production from both partonic and hadronic phases with in-medium broadened ρ0meson. The fraction of direct virtual photons over inclusive virtual photons is extracted for dielectron pairs withinvariant mass 0.1 < mee < 0.3 GeV/c2 and in the transverse-momentum intervals 1 < pT,ee < 2 GeV/c and2 < pT,ee < 4 GeV/c. The measured fraction of virtual direct photons is consistent with the measurement of realdirect photons by ALICE and with the expectations from previous dielectron measurements at RHIC within theexperimental uncertainties.