Details

Autor(en) / Beteiligte

• Agakishiev, G.
• Aggarwal, M. M.
• Ahammed, Z.
• Alford, J.
• Averichev, G. S.
• Bielcik, J.
• Bland, L. C.
• Bouchet, J.
• Calderón de la Barca Sánchez, M.
• Cebra, D.
• Cervantes, M. C.
• Chattopadhyay, S.
• Contin, G.
• Debbe, R. R.
• Derevschikov, A. A.
• Engelage, J.
• Eppley, G.
• Fazio, S.
• Fisyak, Y.
• Flores, C. E.
• Garand, D.
• Greiner, L.
• Gupta, S.
• Gupta, A.
• Hamad, A.
• Hamed, A.
• Hofman, D. J.
• Horvat, S.
• Humanic, T. J.
• Jang, H.
• Kang, K.
• Ke, H. W.
• Kechechyan, A.
• Koetke, D. D.
• Kosarzewski, L. K.
• Kraishan, A. F.
• Kulakov, I.
• Lauret, J.
• Lee, J. H.
• Li, W.
• Li, Y.
• Llope, W. J.
• Masui, H.
• Matis, H. S.
• McDonald, D.
• Nogach, L. V.
• Novak, J.
• Oh, K.
• Pan, Y. X.
• Pandit, Y.
• Pei, H.
• Peterson, A.
• Pluta, J.
• Poniatowska, K.
• Porter, J.
• Qiu, H.
• Quintero, A.
• Ramachandran, S.
• Raniwala, S.
• Romero, J. L.
• Rusnakova, O.
• Sahoo, N. R.
• Sahu, P. K.
• Salur, S.
• Sandweiss, J.
• Shah, N.
• Shahaliev, E.
• Shanmuganathan, P. V.
• Sharma, B.
• Sikora, R.
• Smirnov, N.
• Srivastava, B.
• Strikhanov, M.
• Sumbera, M.
• Summa, B.
• Sun, Y.
• Timmins, A. R.
• Tokarev, M.
• Tripathy, S. K.
• Trzeciak, B. A.
• Tsai, O. D.
• Vandenbroucke, M.
• Vasiliev, A. N.
• Vertesi, R.
• Voloshin, S. A.
• Wang, J. S.
• Wen, L.
• Wissink, S. W.
• Wu, Y. F.
• Xiao, Z. G.
• Xu, H.
• Ye, Z.
• Yip, K.
• Yoo, I. -K.
• Yu, N.
• Zha, W.
• Zhang, J.
• Zhang, J. B.
• Zhao, J.
• Zhong, C.

Titel

Measurements of dielectron production in Au + Au collisions at sNN=200 GeV from the STAR experiment

Ist Teil von

• Physical review. C, Nuclear physics, 2015-08, Vol.92 (2)

Ort / Verlag

United States: American Physical Society (APS)

Erscheinungsjahr

2015

Quelle

American Physical Society [PROLA]

Beschreibungen/Notizen

• We report on measurements of dielectron (e⁺e⁻) production in Au+Au collisions at a center-of-mass energy of 200 GeV per nucleon-nucleon pair using the STAR detector at RHIC. Systematic measurements of the dielectron yield as a function of transverse momentum (pT) and collision centrality show an enhancement compared to a cocktail simulation of hadronic sources in the low invariant-mass region (Mee < 1GeV/c2). This enhancement cannot be reproduced by the ρ-meson vacuum spectral function. In minimum-bias collisions, in the invariant-mass range of 0.30 – 0.76GeV/c², integrated over the full pT acceptance, the enhancement factor is 1.76±0.06(stat.)±0.26(sys.)±0.29(cocktail). The enhancement factor exhibits weak centrality and pT dependence in STAR's accessible kinematic regions, while the excess yield in this invariant-mass region as a function of the number of participating nucleons follows a power-law shape with a power of 1.44±0.10. Models that assume an in-medium broadening of the ρ-meson spectral function consistently describe the observed excess in these measurements. In addition, we report on measurements of ω- and Φ-meson production through their e⁺e⁻ decay channel. These measurements show good agreement with Tsallis blast-wave model predictions, as well as, in the case of the Φ meson, results through its K⁺K⁻ decay channel. In the intermediate invariant-mass region (1.1 < Mee < 3GeV/c²), we investigate the spectral shapes from different collision centralities. Physics implications for possible in-medium modification of charmed hadron production and other physics sources are discussed.