Measurements of dielectron production in Au+Au collisions at √s.sub.NN./sub.=27, 39, and 62.4 GeV from the STAR experiment

0575514 - ÚJF 2024 RIV US eng J - Článek v odborném periodiku
Abdulhamid, M. I. - Aboona, B. E. - Adam, J. - Adamczyk, L. - Bielčík, J. - Bielčíková, Jana - Češka, J. - Das, A. - Holub, L. - Chaloupka, P. - Kosarzewski, L. K. - Kramárik, L. - Líčeník, Robert - Lomnický, O. - Prozorova, V. - Robotková, Monika - Šumbera, Michal - Truhlář, T. - Trzeciak, B. A. … celkem 366 autorů
Measurements of dielectron production in Au+Au collisions at √s_NN=27, 39, and 62.4 GeV from the STAR experiment.
Physical Review C. Roč. 107, č. 6 (2023), č. článku L061901. ISSN 2469-9985. E-ISSN 2469-9993
Výzkumná infrastruktura: BNL-CZ III - 90234
Institucionální podpora: RVO:61389005
Klíčová slova: STAR collaboration * heavy ion collisions
Obor OECD: Particles and field physics
Impakt faktor: 3.1, rok: 2022
Způsob publikování: Omezený přístup
https://doi.org/10.1103/PhysRevC.107.L061901

We report systematic measurements of dielectron (e+e-) invariant-mass Mee spectra at midrapidity in Au + Au collisions at root sNN = 27, 39, and 62.4 GeV taken with the STAR detector at the Relativistic Heavy Ion Collider. For all energies studied, a significant excess yield of dielectrons is observed in the low-mass region (0.40 < Mee < 0.75 MeV/c2) compared to hadronic cocktail simulations at freeze-out. Models that include an in-medium broadening of the p-meson spectral function consistently describe the observed excess. In addition, we report acceptance-corrected dielectron-excess spectra for Au + Au collisions at midrapidity (|yee| < 1) in the 0-80% centrality bin for each collision energy. The integrated excess yields for 0.4 < Mee < 0.75 GeV/c2, normalized by the charged particle multiplicity at midrapidity, are compared with previously published measurements for Au + Au at sNN = 19.6 and 200 GeV. Models that include an in-medium broadening of the p-meson spectral function consistently describe the observed excess. The normalized excess yields in the low-mass region show no significant collision energy dependence. The data, however, are consistent with model calculations that demonstrate a modest energy dependence.
Trvalý link: https://hdl.handle.net/11104/0345278