Phys. Rev. C
77,
034910
(2008)
[11 pages]
ρ0 photoproduction in ultraperipheral relativistic heavy ion collisions at √sNN=200 GeV
B. I. Abelev et al. STAR Collaboration
Show All Authors/Affiliations
Hide All Authors/Affiliations
B. I. Abelev10, M. M. Aggarwal32, Z. Ahammed47, B. D. Anderson21, D. Arkhipkin14, G. S. Averichev13, Y. Bai30, J. Balewski18, O. Barannikova10, L. S. Barnby2, J. Baudot19, S. Baumgart52, D. R. Beavis3, R. Bellwied50, F. Benedosso30, R. R. Betts10, S. Bhardwaj37, A. Bhasin20, A. K. Bhati32, H. Bichsel49, J. Bielcik12, J. Bielcikova12, L. C. Bland3, S.-L. Blyth24, M. Bombara2, B. E. Bonner38, M. Botje30, J. Bouchet42, E. Braidot30, A. V. Brandin28, S. Bueltmann3, T. P. Burton2, M. Bystersky12, X. Z. Cai41, H. Caines52, M. Calderón de la Barca Sánchez6, J. Callner10, O. Catu52, D. Cebra6, M. C. Cervantes43, Z. Chajecki31, P. Chaloupka12, S. Chattopadhyay47, H. F. Chen40, J. H. Chen41, J. Y. Chen51, J. Cheng45, M. Cherney11, A. Chikanian52, K. E. Choi36, W. Christie3, S. U. Chung3, R. F. Clarke43, M. J. M. Codrington43, J. P. Coffin19, T. M. Cormier50, M. R. Cosentino39, J. G. Cramer49, H. J. Crawford5, D. Das6, S. Dash16, M. Daugherity44, M. M. de Moura39, T. G. Dedovich13, M. DePhillips3, A. A. Derevschikov34, R. Derradi de Souza8, L. Didenko3, T. Dietel15, P. Djawotho18, S. M. Dogra20, X. Dong24, J. L. Drachenberg43, J. E. Draper6, F. Du52, J. C. Dunlop3, M. R. Dutta Mazumdar47, W. R. Edwards24, L. G. Efimov13, E. Elhalhuli2, V. Emelianov28, J. Engelage5, G. Eppley38, B. Erazmus42, M. Estienne19, L. Eun33, P. Fachini3, R. Fatemi22, J. Fedorisin13, A. Feng51, P. Filip14, E. Finch52, V. Fine3, Y. Fisyak3, J. Fu51, C. A. Gagliardi43, L. Gaillard2, M. S. Ganti47, E. Garcia-Solis10, V. Ghazikhanian7, P. Ghosh47, Y. N. Gorbunov11, A. Gordon3, O. Grebenyuk30, D. Grosnick46, B. Grube36, S. M. Guertin7, K. S. F. F. Guimaraes39, A. Gupta20, N. Gupta20, W. Guryn3, B. Haag6, T. J. Hallman3, A. Hamed43, J. W. Harris52, W. He18, M. Heinz52, T. W. Henry43, S. Hepplemann33, B. Hippolyte19, A. Hirsch35, E. Hjort24, A. M. Hoffman25, G. W. Hoffmann44, D. J. Hofman10, R. S. Hollis10, M. J. Horner24, H. Z. Huang7, E. W. Hughes4, T. J. Humanic31, G. Igo7, A. Iordanova10, P. Jacobs24, W. W. Jacobs18, P. Jakl12, F. Jin41, P. G. Jones2, E. G. Judd5, S. Kabana42, K. Kajimoto44, K. Kang45, J. Kapitan12, M. Kaplan9, D. Keane21, A. Kechechyan13, D. Kettler49, V. Yu. Khodyrev34, J. Kiryluk24, A. Kisiel31, S. R. Klein24, A. G. Knospe52, A. Kocoloski25, D. D. Koetke46, T. Kollegger15, M. Kopytine21, L. Kotchenda28, V. Kouchpil12, K. L. Kowalik24, P. Kravtsov28, V. I. Kravtsov34, K. Krueger1, C. Kuhn19, A. Kumar32, P. Kurnadi7, M. A. C. Lamont3, J. M. Landgraf3, S. Lange15, S. LaPointe50, F. Laue3, J. Lauret3, A. Lebedev3, R. Lednicky14, C.-H. Lee36, M. J. LeVine3, C. Li40, Q. Li50, Y. Li45, G. Lin52, X. Lin51, S. J. Lindenbaum29, M. A. Lisa31, F. Liu51, H. Liu40, J. Liu38, L. Liu51, T. Ljubicic3, W. J. Llope38, R. S. Longacre3, W. A. Love3, Y. Lu40, T. Ludlam3, D. Lynn3, G. L. Ma41, J. G. Ma7, Y. G. Ma41, D. P. Mahapatra16, R. Majka52, L. K. Mangotra20, R. Manweiler46, S. Margetis21, C. Markert44, H. S. Matis24, Yu. A. Matulenko34, T. S. McShane11, A. Meschanin34, J. Millane25, M. L. Miller25, N. G. Minaev34, S. Mioduszewski43, A. Mischke30, J. Mitchell38, B. Mohanty47, D. A. Morozov34, M. G. Munhoz39, B. K. Nandi17, C. Nattrass52, T. K. Nayak47, J. M. Nelson2, C. Nepali21, P. K. Netrakanti35, M. J. Ng5, L. V. Nogach34, S. B. Nurushev34, G. Odyniec24, A. Ogawa3, H. Okada3, V. Okorokov28, D. Olson24, M. Pachr12, S. K. Pal47, Y. Panebratsev13, A. I. Pavlinov50, T. Pawlak48, T. Peitzmann30, V. Perevoztchikov3, C. Perkins5, W. Peryt48, S. C. Phatak16, M. Planinic53, J. Pluta48, N. Poljak53, N. Porile35, A. M. Poskanzer24, M. Potekhin3, B. V. K. S. Potukuchi20, D. Prindle49, C. Pruneau50, N. K. Pruthi32, J. Putschke52, I. A. Qattan18, R. Raniwala37, S. Raniwala37, R. L. Ray44, D. Relyea4, A. Ridiger28, H. G. Ritter24, J. B. Roberts38, O. V. Rogachevskiy13, J. L. Romero6, A. Rose24, C. Roy42, L. Ruan3, M. J. Russcher30, V. Rykov21, R. Sahoo42, I. Sakrejda24, T. Sakuma25, S. Salur52, J. Sandweiss52, M. Sarsour43, J. Schambach44, R. P. Scharenberg35, N. Schmitz26, J. Seger11, I. Selyuzhenkov50, P. Seyboth26, A. Shabetai19, E. Shahaliev13, M. Shao40, M. Sharma32, X.-H. Shi41, E. P. Sichtermann24, F. Simon26, R. N. Singaraju47, M. J. Skoby35, N. Smirnov52, R. Snellings30, P. Sorensen3, J. Sowinski18, J. Speltz19, H. M. Spinka1, B. Srivastava35, A. Stadnik13, T. D. S. Stanislaus46, D. Staszak7, R. Stock15, M. Strikhanov28, B. Stringfellow35, A. A. P. Suaide39, M. C. Suarez10, N. L. Subba21, M. Sumbera12, X. M. Sun24, Z. Sun23, B. Surrow25, T. J. M. Symons24, A. Szanto de Toledo39, J. Takahashi8, A. H. Tang3, Z. Tang40, T. Tarnowsky35, D. Thein44, J. H. Thomas24, J. Tian41, A. R. Timmins2, S. Timoshenko28, M. Tokarev13, T. A. Trainor49, V. N. Tram24, A. L. Trattner5, S. Trentalange7, R. E. Tribble43, O. D. Tsai7, J. Ulery35, T. Ullrich3, D. G. Underwood1, G. Van Buren3, N. van der Kolk30, M. van Leeuwen24, A. M. Vander Molen27, R. Varma17, G. M. S. Vasconcelos8, I. M. Vasilevski14, A. N. Vasiliev34, R. Vernet19, F. Videbaek3, S. E. Vigdor18, Y. P. Viyogi16, S. Vokal13, S. A. Voloshin50, M. Wada44, W. T. Waggoner11, F. Wang35, G. Wang7, J. S. Wang23, Q. Wang35, X. Wang45, X. L. Wang40, Y. Wang45, J. C. Webb46, G. D. Westfall27, C. Whitten Jr.7, H. Wieman24, S. W. Wissink18, R. Witt52, J. Wu40, Y. Wu51, N. Xu24, Q. H. Xu24, Z. Xu3, P. Yepes38, I.-K. Yoo36, Q. Yue45, M. Zawisza48, H. Zbroszczyk48, W. Zhan23, H. Zhang3, S. Zhang41, W. M. Zhang21, Y. Zhang40, Z. P. Zhang40, Y. Zhao40, C. Zhong41, J. Zhou38, R. Zoulkarneev14, Y. Zoulkarneeva14, and J. X. Zuo41 (STAR Collaboration)
1Argonne National Laboratory, Argonne, Illinois 60439, USA
2University of Birmingham, Birmingham, United Kingdom
3Brookhaven National Laboratory, Upton, New York 11973, USA
4California Institute of Technology, Pasadena, California 91125, USA
5University of California, Berkeley, California 94720, USA
6University of California, Davis, California 95616, USA
7University of California, Los Angeles, California 90095, USA
8Universidade Estadual de Campinas, Sao Paulo, Brazil
9Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
10University of Illinois at Chicago, Chicago, Illinois 60607, USA
11Creighton University, Omaha, Nebraska 68178, USA
12Nuclear Physics Institute AS CR, 250 68 Řež, Prague, Czech Republic
13Laboratory for High Energy (JINR), Dubna, Russia
14Particle Physics Laboratory (JINR), Dubna, Russia
15University of Frankfurt, Frankfurt, Germany
16Institute of Physics, Bhubaneswar 751005, India
17Indian Institute of Technology, Mumbai, India
18Indiana University, Bloomington, Indiana 47408, USA
19Institut de Recherches Subatomiques, Strasbourg, France
20University of Jammu, Jammu 180001, India
21Kent State University, Kent, Ohio 44242, USA
22University of Kentucky, Lexington, Kentucky 40506-0055, USA
23Institute of Modern Physics, Lanzhou, China
24Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
25Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA
26Max-Planck-Institut für Physik, Munich, Germany
27Michigan State University, East Lansing, Michigan 48824, USA
28Moscow Engineering Physics Institute, Moscow, Russia
29City College of New York, New York City, New York 10031, USA
30NIKHEF and Utrecht University, Amsterdam, The Netherlands
31Ohio State University, Columbus, Ohio 43210, USA
32Panjab University, Chandigarh 160014, India
33Pennsylvania State University, University Park, Pennsylvania 16802, USA
34Institute of High Energy Physics, Protvino, Russia
35Purdue University, West Lafayette, Indiana 47907, USA
36Pusan National University, Pusan, Republic of Korea
37University of Rajasthan, Jaipur 302004, India
38Rice University, Houston, Texas 77251, USA
39Universidade de Sao Paulo, Sao Paulo, Brazil
40University of Science & Technology of China, Hefei 230026, China
41Shanghai Institute of Applied Physics, Shanghai 201800, China
42SUBATECH, Nantes, France
43Texas A&M University, College Station, Texas 77843, USA
44University of Texas, Austin, Texas 78712, USA
45Tsinghua University, Beijing 100084, China
46Valparaiso University, Valparaiso, Indiana 46383, USA
47Variable Energy Cyclotron Centre, Kolkata 700064, India
48Warsaw University of Technology, Warsaw, Poland
49University of Washington, Seattle, Washington 98195, USA
50Wayne State University, Detroit, Michigan 48201, USA
51Institute of Particle Physics, CCNU (HZNU), Wuhan 430079, China
52Yale University, New Haven, Connecticut 06520, USA
53University of Zagreb, Zagreb HR-10002, Croatia
Received 21 December 2007; published 31 March 2008
Photoproduction reactions occur when the electromagnetic field of a relativistic heavy ion interacts with another heavy ion. The STAR Collaboration presents a measurement of ρ0 and direct π+π- photoproduction in ultraperipheral relativistic heavy ion collisions at √sNN=200 GeV. We observe both exclusive photoproduction and photoproduction accompanied by mutual Coulomb excitation. We find a coherent cross section of σ(AuAu→Au*Au*ρ0)=530±19(stat.)±57(syst.) mb, in accord with theoretical calculations based on a Glauber approach, but considerably below the predictions of a color dipole model. The ρ0 transverse momentum spectrum (pT2) is fit by a double exponential curve including both coherent and incoherent coupling to the target nucleus; we find σinc/σcoh=0.29±0.03(stat.)±0.08(syst.). The ratio of direct π+π- to ρ0 production is comparable to that observed in γp collisions at HERA and appears to be independent of photon energy. Finally, the measured ρ0 spin helicity matrix elements agree within errors with the expected s-channel helicity conservation.
© 2008 The American Physical Society
URL:
http://link.aps.org/doi/10.1103/PhysRevC.77.034910
DOI:
10.1103/PhysRevC.77.034910
PACS:
25.20.Lj, 13.60.-r, 25.75.Cj, 25.75.Dw
|
|
