Dielectron production in Au + Au collisions at √sNN = 200 GeV

Znanstveni rad - Izvorni znanstveni rad

• Autor: A. Adare
• Autor: ...
• Autor: Mihael Makek
• Autor: ...
• Autor: L. Zou
• Kolaboracija: PHENIX Collaboration
• Autorova ustanova: Sveučilište u Zagrebu; Prirodoslovno-matematički fakultet; (Fizički odsjek)
• Znanstveno / umjetničko područje, polje i grana: PRIRODNE ZNANOSTI; Fizika

Sažetak (engleski)

We present measurements of e+e− production at midrapidity in Au + Au collisions at √sNN = 200 GeV. The invariant yield is studied within the PHENIX detector acceptance over a wide range of mass (mee < 5 GeV/c2) and pair transverse momentum (pT < 5 GeV/c) for minimum bias and for five centrality classes. The e+e− yield is compared to the expectations from known sources. In the low-mass region (mee = 0.30–0.76 GeV/c2) there is an enhancement that increases with centrality and is distributed over the entire pair pT range measured. It is significantly smaller than previously reported by the PHENIX experiment and amounts to 2.3 ± 0.4(stat) ± 0.4(syst) ± 0.2(model) or to 1.7 ± 0.3(stat) ± 0.3(syst) ± 0.2(model) for minimum bias collisions when the open heavy-flavor contribution is calculated with PYTHIA or MC@NLO, respectively. The inclusive mass and pT distributions, as well as the centrality dependence, are well reproduced by model calculations where the enhancement mainly originates from the melting of the ρ meson resonance as the system approaches chiral symmetry restoration. In the intermediate-mass region (mee = 1.2–2.8 GeV/c2), the data hint at a significant contribution in addition to the yield from the semileptonic decays of heavy-flavor mesons.

• Ključne riječi (engleski): QGP; dielectrons; HBD; PHENIX
• Jezik: engleski
• Vrsta publikacije: Znanstveni rad - Izvorni znanstveni rad
• Status objave: Objavljen
• Vrsta recenzije: Recenziran - međunarodna recenzija
• Verzija publikacije: Objavljena verzija rada (izdavačev PDF)
• Naslov časopisa: Physical Review C - Nuclear Physics
• Brojčani podaci: vol. 93, br. 1, 014904
• p-ISSN: 0556-2813
• e-ISSN: 1089-490X
• DOI: https://doi.org/10.1103/PhysRevC.93.014904
• URN:NBN: urn:nbn:hr:217:006069
• Datum objave publikacije: 2016
• URL dokumenta: https://journals.aps.org/prc/abstract/10.1103/PhysRevC.93.014904
• Vrsta resursa: Tekst
• Prava pristupa: Otvoreni pristup
• Javna napomena: Copyright (2016) by the American Physical Society. Received 5 October 2015; published 11 January 2016.
• Datum i vrijeme pohrane: 2020-02-09 14:45:03