Direct photon production in Pb-Pb collisions at √sNN=2.76 TeV

被引：189

作者：

Adam, J. ^{[54
,55
]}

Adamova, D. ^{[99
]}

Aggarwal, M. M. ^{[103
]}

Rinella, G. Aglieri ^{[50
]}

Agnello, M. ^{[127
]}

Agrawal, N. ^{[64
]}

Ahammed, Z. ^{[149
]}

Ahn, S. U. ^{[84
]}

Aiola, S. ^{[153
]}

Akindinov, A. ^{[74
,113
]}

Alam, S. N. ^{[149
]}

Aleksandrov, D. ^{[116
]}

Alessandro, B. ^{[127
]}

Alexandre, D. ^{[118
]}

Molina, R. Alfaro ^{[80
]}

Alici, A. ^{[14
,15
,121
]}

Alkin, A. ^{[3
]}

Almaraz, J. R. M. ^{[136
]}

Alme, J. ^{[52
]}

Alt, T. ^{[59
]}

Altinpinar, S. ^{[22
]}

Altsybeev, I. ^{[148
]}

Prado, C. Alves Garcia ^{[137
]}

Andrei, C. ^{[94
]}

Andronic, A. ^{[112
,113
]}

Anguelov, V. ^{[109
]}

Anielski, J. ^{[70
]}

Anticic, T. ^{[114
]}

Antinori, F. ^{[124
]}

Antonioli, P. ^{[121
]}

Aphecetche, L. ^{[130
]}

Appelshauser, H. ^{[69
]}

Arcelli, S. ^{[36
,37
]}

Arnaldi, R. ^{[127
]}

Arnold, O. W. ^{[51
,108
]}

Arsene, I. C. ^{[26
]}

Arslandok, M. ^{[69
]}

Audurier, B. ^{[130
]}

Augustinus, A. ^{[50
]}

Averbeck, R. ^{[112
,113
]}

Awes, T. C. ^{[100
]}

Azmi, M. D. ^{[23
]}

Badala, A. ^{[123
]}

Baek, Y. W. ^{[60
,83
]}

Bagnasco, S. ^{[127
]}

Bailhache, R. ^{[69
]}

Bala, R.

Baldisseri, A. ^{[18
]}

Baral, R. C. ^{[77
]}

Barbano, A. M. ^{[34
,35
]}

机构：

[1] Yerevan Phys Inst Fdn, AI Alikhanyan Natl Sci Lab, Yerevan, Armenia

[2] Benemerita Univ Autonoma Puebla, Puebla, Mexico

[3] Bogolyubov Inst Theoret Phys, Kiev, Ukraine

[4] Bose Inst, Dept Phys, Kolkata, India

[5] CAPSS, Kolkata, India

[6] Budker Inst Nucl Phys, Novosibirsk 630090, Russia

[7] Calif Polytech State Univ San Luis Obispo, San Luis Obispo, CA 93407 USA

[8] Cent China Normal Univ, Wuhan, Peoples R China

[9] IN2P3, Ctr Calcul, Villeurbanne, France

[10] Ctr Aplicac Tecnol & Desarrollo Nucl CEADEN, Havana, Cuba

[11] CIEMAT, Madrid, Spain

[12] CINVESTAV, Mexico City 14000, DF, Mexico

[13] CINVESTAV, Merida, Mexico

[14] Museo Stor Fis, Ctr Fermi, Rome, Italy

[15] Ctr Studi & Ric Enrico Fermi, Rome, Italy

[16] Chicago State Univ, Chicago, IL USA

[17] China Inst Atom Energy, Beijing, Peoples R China

[18] CEA, IRFU, Saclay, France

[19] COMSATS Inst Informat Technol CIIT, Islamabad, Pakistan

[20] Univ Santiago de Compostela, Dept Fis Particulas, Santiago De Compostela, Spain

[21] Univ Santiago de Compostela, IGFAE, Santiago De Compostela, Spain

[22] Univ Bergen, Dept Phys & Technol, Bergen, Norway

[23] Aligarh Muslim Univ, Dept Phys, Aligarh 202002, Uttar Pradesh, India

[24] Ohio State Univ, Dept Phys, 174 W 18th Ave, Columbus, OH 43210 USA

[25] Sejong Univ, Dept Phys, Seoul, South Korea

[26] Univ Oslo, Dept Phys, Oslo, Norway

[27] Politecn Bari, Dipartimento Elettrotecn & Elettron, Bari, Italy

[28] Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy

[29] Sez INFN Rome, Rome, Italy

[30] Univ Cagliari, Dipartimento Fis, Cagliari, Italy

[31] Sezione Ist Nazl Fis Nucl, Cagliari, Italy

[32] Univ Trieste, Dipartimento Fis, Trieste, Italy

[33] Sezione Ist Nazl Fis Nucl, Trieste, Italy

[34] Univ Turin, Dipartimento Fis, Turin, Italy

[35] Sezione Ist Nazl Fis Nucl, Turin, Italy

[36] Univ Bologna, Dipartimento Fis & Astron, Bologna, Italy

[37] Sezione Ist Nazl Fis Nucl, Bologna, Italy

[38] Univ Catania, Dipartimento Fis & Astron, Catania, Italy

[39] Sezione Ist Nazl Fis Nucl, Catania, Italy

[40] Univ Padua, Dipartimento Fis & Astron, Padua, Italy

[41] Sezione Ist Nazl Fis Nucl, Padua, Italy

[42] Univ Salerno, Dipartimento Fis ER Caianiello, I-84100 Salerno, Italy

[43] Ist Nazl Fis Nucl, Grp Collegato, Salerno, Italy

[44] Univ Piemonte Orientale, Dipartimento Sci & Innovaz Tecnol, Alessandria, Italy

[45] INFN, Grp Collegato, Alessandria, Italy

[46] Dipartimento Interateneo Fis M Merlin, Bari, Italy

[47] Sezione Ist Nazl Fis Nucl, Bari, Italy

[48] Lund Univ, Div Expt High Energy Phys, Lund, Sweden

[49] Univ Tubingen, Tubingen, Germany

[50] CERN, European Org Nucl Res, CH-1211 Geneva, Switzerland

来源：

PHYSICS LETTERS B | 2016年 / 754卷

基金：

美国国家科学基金会;

关键词：

QUARK-GLUON PLASMA; NUCLEUS-NUCLEUS COLLISIONS; EQUATION-OF-STATE; TRANSVERSE-MOMENTUM; THERMAL PHOTONS; NEUTRAL PION; FRAGMENTATION; PERSPECTIVE; DEPENDENCE; FLOW;

D O I：

10.1016/j.physletb.2016.01.020

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Direct photon production at mid-rapidity in Pb-Pb collisions at root s(NN) = 2.76 TeV was studied in the transverse momentum range 0.9 < p(T) < 14 GeV/c. Photons were detected with the highly segmented electromagnetic calorimeter PHOS and via conversions in the ALICE detector material with the e(+)e(-) pair reconstructed in the central tracking system. The results of the two methods were combined and direct photon spectra were measured for the 0-20%, 20-40%, and 40-80% centrality classes. For all three classes, agreement was found with perturbative QCD calculations for p(T) greater than or similar to 5 GeV/c. Direct photon spectra down to p(T) approximate to 1 GeV/c could be extracted for the 20-40% and 0-20% centrality classes. The significance of the direct photon signal for 0.9 < p(T) < 2.1 GeV/c is 2.6 sigma for the 0-20% class. The spectrum in this p(T) range and centrality class can be described by an exponential with an inverse slope parameter of (297 +/- 12(stat) +/- 41(syst)) MeV. State-of-the-art models for photon production in heavy-ion collisions agree with the data within uncertainties. (C) 2016 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.

引用

页码：235 / 248

页数：14

共 73 条

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