Evidence for the production of thermal muon pairs with masses above 1 GeV/c 2 in 158 A GeV indium-indium collisions

被引：89

作者：

Arnaldi, R. ^{[1
,2
]}

Banicz, K. ^{[7
,10
]}

Borer, K. ^{[3
]}

Castor, J. ^{[8
,9
]}

Chaurand, B. ^{[14
,15
]}

Chen, W. ^{[4
]}

Cicalo, C. ^{[5
,6
]}

Colla, A. ^{[1
,2
]}

Cortese, P. ^{[1
,2
]}

Damjanovic, S. ^{[7
,10
]}

David, A. ^{[7
,11
]}

de Falco, A. ^{[5
,6
]}

Devaux, A. ^{[8
,9
]}

Ducroux, L. ^{[12
,13
]}

En'yo, H. ^{[16
]}

Fargeix, J. ^{[8
,9
]}

Ferretti, A. ^{[1
,2
]}

Floris, M. ^{[5
,6
]}

Foerster, A. ^{[7
]}

Force, P. ^{[8
,9
]}

Guettet, N. ^{[7
,8
,9
]}

Guichard, A. ^{[12
,13
]}

Gulkanian, H. ^{[17
]}

Heuser, J. M. ^{[16
]}

Keil, M. ^{[7
,11
]}

Kluberg, L. ^{[14
,15
]}

Li, Z. ^{[4
]}

Lourenco, C. ^{[7
]}

Lozano, J. ^{[11
]}

Manso, F. ^{[8
,9
]}

Martins, P. ^{[7
,11
]}

Masoni, A. ^{[5
,6
]}

Neves, A. ^{[11
]}

Ohnishi, H. ^{[16
]}

Oppedisano, C. ^{[1
,2
]}

Parracho, P. ^{[7
,11
]}

Pillot, P. ^{[12
,13
]}

Poghosyan, T. ^{[17
]}

Puddu, G. ^{[5
,6
]}

Radermacher, E. ^{[7
]}

Ramalhete, P. ^{[7
,11
]}

Rosinsky, P. ^{[7
]}

Scomparin, E. ^{[1
,2
]}

Seixas, J. ^{[11
]}

Serci, S. ^{[5
,6
]}

Shahoyan, R. ^{[7
,11
]}

Sonderegger, P. ^{[11
]}

Specht, H. J. ^{[10
]}

Tieulent, R. ^{[12
,13
]}

Usai, G. ^{[5
,6
]}

机构：

[1] Univ Turin, Turin, Italy

[2] Ist Nazl Fis Nucl, I-10125 Turin, Italy

[3] High Energy Phys Lab, Bern, Switzerland

[4] BNL, Upton, NY USA

[5] Univ Cagliari, Cagliari, Italy

[6] Ist Nazl Fis Nucl, Cagliari, Italy

[7] CERN, Geneva, Switzerland

[8] Univ Blaise Pascal, LPC, Clermont Ferrand, France

[9] CNRS, IN2P3, Clermont Ferrand, France

[10] Heidelberg Univ, Inst Phys, D-6900 Heidelberg, Germany

[11] IST CFTP, Lisbon, Portugal

[12] Univ Lyon 1, IPN Lyon, F-69365 Lyon, France

[13] CNRS, IN2P3, Lyon, France

[14] Ecole Polytech, LLR, Palaiseau, France

[15] Ecole Polytech, CNRS, IN2P3, F-91128 Palaiseau, France

[16] RIKEN, Wako, Saitama, Japan

[17] YerPhI, Yerevan, Armenia

来源：

EUROPEAN PHYSICAL JOURNAL C | 2009年 / 59卷 / 03期

关键词：

PB-PB INTERACTIONS; DILEPTON RADIATION; CHARM PRODUCTION; CROSS-SECTIONS; FIXED-TARGET; HEAVY; ENHANCEMENT; DIMUON; J/PSI;

D O I：

10.1140/epjc/s10052-008-0857-2

中图分类号：

O412 [相对论、场论]; O572.2 [粒子物理学];

学科分类号：

摘要：

The yield of muon pairs in the invariant mass region 1 < M < 2.5 GeV/c (2) produced in heavy-ion collisions significantly exceeds the sum of the two expected contributions, Drell-Yan dimuons and muon pairs from the decays of D meson pairs. These sources properly account for the dimuons produced in proton-nucleus collisions. In this paper, we show that dimuons are also produced in excess in 158 A GeV In-In collisions. We furthermore observe, by tagging the dimuon vertices, that this excess is not due to enhanced D meson production, but made of prompt muon pairs, as expected from a source of thermal dimuons specific to high-energy nucleus-nucleus collisions. The yield of this excess increases significantly from peripheral to central collisions, both with respect to the Drell-Yan yield and to the number of nucleons participating in the collisions. Furthermore, the transverse mass distributions of the excess dimuons are well described by an exponential function, with inverse slope values around 190 MeV. The values are independent of mass and significantly lower than those found at masses below 1 GeV/c (2), rising there up to 250 MeV due to radial flow. This suggests the emission source of thermal dimuons above 1 GeV/c (2) to be of largely partonic origin, when radial flow has not yet built up.

引用

页码：607 / 623

页数：17

共 42 条

[1] Dimuon and charm production in nucleus-nucleus collisions at the CERN-SPS [J].

Abreu, MC ;

Alessandro, B ;

Alexa, C ;

Arnaldi, R ;

Astruc, J ;

Atayan, M ;

Baglin, C ;

Baldit, A ;

Bedjidian, M ;

Bellaiche, F ;

Beolé, S ;

Boldea, V ;

Bordalo, P ;

Borhani, A ;

Bussière, A ;

Capelli, L ;

Capony, V ;

Casagrande, L ;

Castor, J ;

Chambon, T ;

Chaurand, B ;

Chevrot, I ;

Cheynis, B ;

Chiavassa, E ;

Cicalò, C ;

Claudino, T ;

Comets, MP ;

Constans, N ;

Constantinescu, S ;

Cruz, J ;

De Falco, A ;

De Marco, N ;

Dellacasa, G ;

Devaux, A ;

Dita, S ;

Drapier, O ;

Ducroux, L ;

Espagnon, B ;

Fargeix, J ;

Fleuret, F ;

Force, P ;

Gallio, M ;

Gavrilov, YK ;

Gerschel, C ;

Giubellino, P ;

Golubeva, MB ;

Gonin, M ;

Grigorian, AA ;

Grossiord, JY ;

Guber, FF .

EUROPEAN PHYSICAL JOURNAL C, 2000, 14 (03) :443-455

[2] Anomalous J/psi suppression in Pb-Pb interactions at 158 GeV/c per nucleon [J].

Abreu, MC ;

Alessandro, B ;

Alexa, C ;

Astruc, J ;

Baglin, C ;

Baldit, A ;

Bedjidian, M ;

Bellaiche, F ;

Beole, S ;

Boldea, V ;

Bonazzola, G ;

Bordalo, P ;

Borhani, A ;

Bussiere, A ;

Capony, V ;

Castor, J ;

Chambon, T ;

Chaurand, B ;

Chevrot, I ;

Cheynis, B ;

Chiavassa, E ;

Cicalo, C ;

Constantinescu, S ;

Cruz, J ;

Dabrowski, W ;

DeFalco, A ;

Dellacasa, G ;

DeMarco, N ;

Devaux, A ;

Dita, S ;

Drapier, O ;

Espagnon, B ;

Fargeix, J ;

Fleuret, F ;

Force, P ;

Gallio, M ;

Gatignon, L ;

Gavrilov, YK ;

Gerschel, C ;

Giubellino, P ;

Golubeva, MB ;

Gonin, M ;

Gorodetzky, P ;

Grossiord, JY ;

Guaita, P ;

Guber, FF ;

Guichard, A ;

Haroutunian, R ;

Idzik, M ;

Jouan, D .

PHYSICS LETTERS B, 1997, 410 (2-4) :337-343

[3] J/psi and Drell-Yan cross-sections in Pb-Pb interactions at 158 GeV/c per nucleon [J].

Abreu, MC ;

Alessandro, B ;

Alexa, C ;

Astruc, J ;

Baglin, C ;

Baldit, A ;

Bedjidian, M ;

Bellaiche, F ;

Beole, S ;

Boldea, V ;

Bonazzola, G ;

Bordalo, P ;

Borhani, A ;

Bussiere, A ;

Capony, V ;

Castor, J ;

Chambon, T ;

Chaurand, B ;

Chevrot, I ;

Cheynis, B ;

Chiavassa, E ;

Cicalo, C ;

Constantinescu, S ;

Cruz, J ;

Dabrowski, W ;

DeFalco, A ;

Dellacasa, G ;

DeMarco, N ;

Devaux, A ;

Dita, S ;

Drapier, O ;

Espagnon, B ;

Fargeix, J ;

Fleuret, F ;

Force, P ;

Gallio, M ;

Gatignon, L ;

Gavrilov, YK ;

Gerschel, C ;

Giubellino, P ;

Golubeva, MB ;

Gonin, M ;

Gorodetzky, P ;

Grossiord, JY ;

Guaita, P ;

Guber, FF ;

Guichard, A ;

Haroutunian, R ;

Idzik, M ;

Jouan, D .

PHYSICS LETTERS B, 1997, 410 (2-4) :327-336

[4]

Alessandro B, 2005, EUR PHYS J C, V39, P335, DOI 10.1140/epjc/s2004-02107-9

[5] Chronic antipsychotic treatment selectively alters nerve growth factor and neuropeptide Y immunoreactivity and the distribution of choline acetyl transferase in rat brain regions [J].

Angelucci, F ;

Aloe, L ;

Gruber, SHM ;

Fiore, M ;

Mathé, AA .

INTERNATIONAL JOURNAL OF NEUROPSYCHOPHARMACOLOGY, 2000, 3 (01) :13-25

[6]

[Anonymous], GEANT

[7] J/ψ production in indium-indium collisions at 158 GeV/Nucleon [J].

Arnaldi, R. ;

Banicz, K. ;

Castor, J. ;

Chaurand, B. ;

Cicalo, C. ;

Colla, A. ;

Cortese, P. ;

Damjanovic, S. ;

David, A. ;

de Falco, A. ;

Devaux, A. ;

Ducroux, L. ;

En'yo, H. ;

Fargeix, J. ;

Ferretti, A. ;

Floris, M. ;

Forster, A. ;

Force, P. ;

Guettet, N. ;

Guichard, A. ;

Gulkanian, H. ;

Heuser, J. M. ;

Keil, M. ;

Kluberg, L. ;

Lourenco, C. ;

Lozano, J. ;

Manso, F. ;

Martins, P. ;

Masoni, A. ;

Neves, A. ;

Ohnishi, H. ;

Oppedisano, C. ;

Parracho, P. ;

Pillot, P. ;

Poghosyan, T. ;

Puddu, G. ;

Radermacher, E. ;

Ramalhete, P. ;

Rosinsky, P. ;

Scomparin, E. ;

Seixas, J. ;

Serci, S. ;

Shahoyan, R. ;

Sonderegger, P. ;

Specht, H. J. ;

Tieulent, R. ;

Usai, G. ;

Veenhof, R. ;

Wohri, H. K. .

PHYSICAL REVIEW LETTERS, 2007, 99 (13)

[8] Evidence for radial flow of thermal dileptons in high-energy nuclear collisions [J].

Arnaldi, R. ;

Banicz, K. ;

Castor, J. ;

Chaurand, B. ;

Cicalo, C. ;

Colla, A. ;

Cortese, P. ;

Damjanovic, S. ;

David, A. ;

de Falco, A. ;

Devaux, A. ;

Ducroux, L. ;

En'yo, H. ;

Fargeix, J. ;

Ferretti, A. ;

Floris, M. ;

Foerster, A. ;

Force, P. ;

Guettet, N. ;

Guichard, A. ;

Gulkanian, H. ;

Heuser, J. M. ;

Keil, M. ;

Kluberg, L. ;

Lourenco, C. ;

Lozano, J. ;

Manso, F. ;

Martins, P. ;

Masoni, A. ;

Neves, A. ;

Ohnishi, H. ;

Oppedisano, C. ;

Parracho, P. ;

Pillot, P. ;

Poghosyan, T. ;

Puddu, G. ;

Radermacher, E. ;

Ramalhete, P. ;

Rosinsky, P. ;

Scomparin, E. ;

Seixas, J. ;

Serci, S. ;

Shahoyan, R. ;

Sonderegger, P. ;

Specht, H. J. ;

Tieulent, R. ;

Usai, G. ;

Veenhof, R. ;

Wohri, H. K. .

PHYSICAL REVIEW LETTERS, 2008, 100 (02)

[9]

BADIER J, 1984, Z PHYS C PART FIELDS, V26, P489, DOI 10.1007/BF01551789

[10]

Capelli L, 2002, NUCL PHYS A, V698, p539C

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