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

PHENIX Collaboration

doi:10.1103/PhysRevC.93.014904

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

PHENIX Collaboration

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Abstract

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.

Original language	English
Article number	014904
Journal	Physical Review C
Volume	93
Issue number	1
DOIs	https://doi.org/10.1103/PhysRevC.93.014904
State	Published - Jan 11 2016
Externally published	Yes

Funding

We thank the staff of the Collider-Accelerator and Physics Departments at Brookhaven National Laboratory and the staff of the other PHENIX participating institutions for their vital contributions. We also thank R. Rapp for providing us the results of his model calculations and for helpful discussions. We acknowledge support from the Office of Nuclear Physics in the Office of Science of the Department of Energy, the National Science Foundation, Abilene Christian University Research Council, Research Foundation of SUNY, and Dean of the College of Arts and Sciences, Vanderbilt University (USA); Ministry of Education, Culture, Sports, Science, and Technology and the Japan Society for the Promotion of Science (Japan) National Science Fund, OTKA, Kroly Robert University College, and the Ch. Simonyi Fund (Hungary); Department of Atomic Energy and Department of Science and Technology (India); Israel Science Foundation (Israel), Basic Science Research Program through NRF of the Ministry of Education (Korea); Physics Department, Lahore University of Management Sciences (Pakistan); Ministry of Education and Science, Russian Academy of Sciences, Federal Agency of Atomic Energy (Russia); VR and Wallenberg Foundation (Sweden); the U.S. Civilian Research and Development Foundation for the Independent States of the Former Soviet Union, the Hungarian American Enterprise Scholarship Fund, and the US-Israel Binational Science Foundation.

Funders	Funder number
Abilene Christian University Research Council
Department of Atomic Energy and Department of Science and Technology
Kroly Robert University College
Research Foundation of SUNY
Wallenberg Foundation
National Science Foundation	1506489
National Science Foundation
U.S. Department of Energy
CRDF Global
Nuclear Physics
Vanderbilt University
Lahore University of Management Sciences
College of Arts and Sciences, Boston University
Department of Physics, Harvard University
Hungarian-American Enterprise Scholarship Fund
Japan Society for the Promotion of Science	15H03664, 26610071
Japan Society for the Promotion of Science
Ministry of Education, Culture, Sports, Science and Technology
United States-Israel Binational Science Foundation
Russian Academy of Sciences
Ministry of Education
Bulgarian National Science Fund
Hungarian Scientific Research Fund
National Research Foundation of Korea
Israel Science Foundation
Vetenskapsrådet
Ministry of Education and Science
Federal Agency of Atomic Energy of the Russian Federation

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10.1103/PhysRevC.93.014904

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@article{f5de5f04274e44e095351c57d8a671cc,

title = "Dielectron production in Au + Au collisions at sNN =200 GeV",

abstract = "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.",

author = "{PHENIX Collaboration} and A. Adare and C. Aidala and Ajitanand, {N. N.} and Y. Akiba and R. Akimoto and J. Alexander and M. Alfred and H. Al-Ta'Ani and A. Angerami and K. Aoki and N. Apadula and Y. Aramaki and H. Asano and Aschenauer, {E. C.} and Atomssa, {E. T.} and R. Averbeck and Awes, {T. C.} and B. Azmoun and V. Babintsev and M. Bai and Bandara, {N. S.} and B. Bannier and Barish, {K. N.} and B. Bassalleck and S. Bathe and V. Baublis and S. Baumgart and A. Bazilevsky and M. Beaumier and S. Beckman and R. Belmont and A. Berdnikov and Y. Berdnikov and Blau, {D. S.} and Bok, {J. S.} and K. Boyle and Brooks, {M. L.} and J. Bryslawskyj and H. Buesching and V. Bumazhnov and S. Butsyk and S. Campbell and P. Castera and Chen, {C. H.} and Chi, {C. Y.} and M. Chiu and V. Cianciolo and I. Garishvili and Lajoie, {J. G.} and Read, {K. F.}",

note = "Publisher Copyright: {\textcopyright} 2016 American Physical Society.",

year = "2016",

month = jan,

day = "11",

doi = "10.1103/PhysRevC.93.014904",

language = "English",

volume = "93",

journal = "Physical Review C",

issn = "2469-9985",

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T1 - Dielectron production in Au + Au collisions at sNN =200 GeV

AU - PHENIX Collaboration

AU - Adare, A.

AU - Aidala, C.

AU - Ajitanand, N. N.

AU - Akiba, Y.

AU - Akimoto, R.

AU - Alexander, J.

AU - Alfred, M.

AU - Al-Ta'Ani, H.

AU - Angerami, A.

AU - Aoki, K.

AU - Apadula, N.

AU - Aramaki, Y.

AU - Asano, H.

AU - Aschenauer, E. C.

AU - Atomssa, E. T.

AU - Averbeck, R.

AU - Awes, T. C.

AU - Azmoun, B.

AU - Babintsev, V.

AU - Bai, M.

AU - Bandara, N. S.

AU - Bannier, B.

AU - Barish, K. N.

AU - Bassalleck, B.

AU - Bathe, S.

AU - Baublis, V.

AU - Baumgart, S.

AU - Bazilevsky, A.

AU - Beaumier, M.

AU - Beckman, S.

AU - Belmont, R.

AU - Berdnikov, A.

AU - Berdnikov, Y.

AU - Blau, D. S.

AU - Bok, J. S.

AU - Boyle, K.

AU - Brooks, M. L.

AU - Bryslawskyj, J.

AU - Buesching, H.

AU - Bumazhnov, V.

AU - Butsyk, S.

AU - Campbell, S.

AU - Castera, P.

AU - Chen, C. H.

AU - Chi, C. Y.

AU - Chiu, M.

AU - Cianciolo, V.

AU - Garishvili, I.

AU - Lajoie, J. G.

AU - Read, K. F.

PY - 2016/1/11

Y1 - 2016/1/11

N2 - 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.

AB - 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.

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U2 - 10.1103/PhysRevC.93.014904

DO - 10.1103/PhysRevC.93.014904

M3 - Article

AN - SCOPUS:85019287872

SN - 2469-9985

VL - 93

JO - Physical Review C

JF - Physical Review C

IS - 1

M1 - 014904

ER -

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

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