Phys. Rev. D
71,
071102(R)
(2005)
[7 pages]
Midrapidity direct-photon production in p+p collisions at √s=200 GeV
S. S. Adler et al. PHENIX Collaboration
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S. S. Adler5, S. Afanasiev17, C. Aidala5, N. N. Ajitanand43, Y. Akiba20,38, J. Alexander43, R. Amirikas12, L. Aphecetche45, S. H. Aronson5, R. Averbeck44, T. C. Awes35, R. Azmoun44, V. Babintsev15, A. Baldisseri10, K. N. Barish6, P. D. Barnes27, B. Bassalleck33, S. Bathe30, S. Batsouli9, V. Baublis37, A. Bazilevsky39,15, S. Belikov16,15, Y. Berdnikov40, S. Bhagavatula16, J. G. Boissevain27, H. Borel10, S. Borenstein25, M. L. Brooks27, D. S. Brown34, N. Bruner33, D. Bucher30, H. Buesching30, V. Bumazhnov15, G. Bunce5,39, J. M. Burward-Hoy26,44, S. Butsyk44, X. Camard45, J.-S. Chai18, P. Chand4, W. C. Chang2, S. Chernichenko15, C. Y. Chi9, J. Chiba20, M. Chiu9, I. J. Choi52, J. Choi19, R. K. Choudhury4, T. Chujo5, V. Cianciolo35, Y. Cobigo10, B. A. Cole9, P. Constantin16, D. d’Enterria45, G. David5, H. Delagrange45, A. Denisov15, A. Deshpande39, E. J. Desmond5, A. Devismes44, O. Dietzsch41, O. Drapier25, A. Drees44, K. A. Drees5, R. du Rietz29, A. Durum15, D. Dutta4, Y. V. Efremenko35, K. El Chenawi49, A. Enokizono14, H. En’yo38,39, S. Esumi48, L. Ewell5, D. E. Fields33,39, F. Fleuret25, S. L. Fokin23, B. D. Fox39, Z. Fraenkel51, J. E. Frantz9, A. Franz5, A. D. Frawley12, S.-Y. Fung6, S. Garpman29,*, T. K. Ghosh49, A. Glenn46, G. Gogiberidze46, M. Gonin25, J. Gosset10, Y. Goto39, R. Granier de Cassagnac25, N. Grau16, S. V. Greene49, M. Grosse Perdekamp39, W. Guryn5, H.-Å. Gustafsson29, T. Hachiya14, J. S. Haggerty5, H. Hamagaki8, A. G. Hansen27, E. P. Hartouni26, M. Harvey5, R. Hayano8, N. Hayashi38, X. He13, M. Heffner26, T. K. Hemmick44, J. M. Heuser44, M. Hibino50, J. C. Hill16, W. Holzmann43, K. Homma14, B. Hong22, A. Hoover34, T. Ichihara38,39, V. V. Ikonnikov23, K. Imai24,38, D. Isenhower1, M. Ishihara38, M. Issah43, A. Isupov17, B. V. Jacak44, W. Y. Jang22, Y. Jeong19, J. Jia44, O. Jinnouchi38, B. M. Johnson5, S. C. Johnson26, K. S. Joo31, D. Jouan36, S. Kametani8,50, N. Kamihara47,38, J. H. Kang52, S. S. Kapoor4, K. Katou50, S. Kelly9, B. Khachaturov51, A. Khanzadeev37, J. Kikuchi50, D. H. Kim31, D. J. Kim52, D. W. Kim19, E. Kim42, G.-B. Kim25, H. J. Kim52, E. Kistenev5, A. Kiyomichi48, K. Kiyoyama32, C. Klein-Boesing30, H. Kobayashi38,39, L. Kochenda37, V. Kochetkov15, D. Koehler33, T. Kohama14, M. Kopytine44, D. Kotchetkov6, A. Kozlov51, P. J. Kroon5, C. H. Kuberg1,27, K. Kurita39, Y. Kuroki48, M. J. Kweon22, Y. Kwon52, G. S. Kyle34, R. Lacey43, V. Ladygin17, J. G. Lajoie16, A. Lebedev16,23, S. Leckey44, D. M. Lee27, S. Lee19, M. J. Leitch27, X. H. Li6, H. Lim42, A. Litvinenko17, M. X. Liu27, Y. Liu36, C. F. Maguire49, Y. I. Makdisi5, A. Malakhov17, V. I. Manko23, Y. Mao7,38, G. Martinez45, M. D. Marx44, H. Masui48, F. Matathias44, T. Matsumoto8,50, P. L. McGaughey27, E. Melnikov15, F. Messer44, Y. Miake48, J. Milan43, T. E. Miller49, A. Milov44,51, S. Mioduszewski5, R. E. Mischke27, G. C. Mishra13, J. T. Mitchell5, A. K. Mohanty4, D. P. Morrison5, J. M. Moss27, F. Mühlbacher44, D. Mukhopadhyay51, M. Muniruzzaman6, J. Murata38,39, S. Nagamiya20, J. L. Nagle9, T. Nakamura14, B. K. Nandi6, M. Nara48, J. Newby46, P. Nilsson29, A. S. Nyanin23, J. Nystrand29, E. O’Brien5, C. A. Ogilvie16, H. Ohnishi5,38, I. D. Ojha49,3, K. Okada38, M. Ono48, V. Onuchin15, A. Oskarsson29, I. Otterlund29, K. Oyama8, K. Ozawa8, D. Pal51, A. P. T. Palounek27, V. Pantuev44, V. Papavassiliou34, J. Park42, A. Parmar33, S. F. Pate34, T. Peitzmann30, J.-C. Peng27, V. Peresedov17, C. Pinkenburg5, R. P. Pisani5, F. Plasil35, M. L. Purschke5, A. K. Purwar44, J. Rak16, I. Ravinovich51, K. F. Read35,46, M. Reuter44, K. Reygers30, V. Riabov37,40, Y. Riabov37, G. Roche28, A. Romana25, M. Rosati16, P. Rosnet28, S. S. Ryu52, M. E. Sadler1, N. Saito38,39, T. Sakaguchi8,50, M. Sakai32, S. Sakai48, V. Samsonov37, L. Sanfratello33, R. Santo30, H. D. Sato24,38, S. Sato5,48, S. Sawada20, Y. Schutz45, V. Semenov15, R. Seto6, M. R. Shaw1,27, T. K. Shea5, T.-A. Shibata47,38, K. Shigaki14,20, T. Shiina27, C. L. Silva41, D. Silvermyr27,29, K. S. Sim22, C. P. Singh3, V. Singh3, M. Sivertz5, A. Soldatov15, R. A. Soltz26, W. E. Sondheim27, S. P. Sorensen46, I. V. Sourikova5, F. Staley10, P. W. Stankus35, E. Stenlund29, M. Stepanov34, A. Ster21, S. P. Stoll5, T. Sugitate14, J. P. Sullivan27, E. M. Takagui41, A. Taketani38,39, M. Tamai50, K. H. Tanaka20, Y. Tanaka32, K. Tanida38, M. J. Tannenbaum5, P. Tarján11, J. D. Tepe1,27, T. L. Thomas33, J. Tojo24,38, H. Torii24,38, R. S. Towell1, I. Tserruya51, H. Tsuruoka48, S. K. Tuli3, H. Tydesjö29, N. Tyurin15, H. W. van Hecke27, J. Velkovska5,44, M. Velkovsky44, V. Veszprémi11, L. Villatte46, A. A. Vinogradov23, M. A. Volkov23, E. Vznuzdaev37, X. R. Wang13, Y. Watanabe38,39, S. N. White5, F. K. Wohn16, C. L. Woody5, W. Xie6, Y. Yang7, A. Yanovich15, S. Yokkaichi38,39, G. R. Young35, I. E. Yushmanov23, W. A. Zajc9,†, C. Zhang9, S. Zhou7, S. J. Zhou51, and L. Zolin17 (PHENIX Collaboration)
1Abilene Christian University, Abilene, Texas 79699, USA 2Institute of Physics, Academia Sinica, Taipei 11529, Taiwan 3Department of Physics, Banaras Hindu University, Varanasi 221005, India 4Bhabha Atomic Research Centre, Bombay 400 085, India 5Brookhaven National Laboratory, Upton, New York 11973-5000, USA 6University of California–Riverside, Riverside, California 92521, USA 7China Institute of Atomic Energy (CIAE), Beijing, People’s Republic of China 8Center for Nuclear Study, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan 9Columbia University, New York, New York 10027, USA, and Nevis Laboratories, Irvington, New York 10533, USA 10Dapnia, CEA Saclay, F-91191, Gif-sur-Yvette, France 11Debrecen University, H-4010 Debrecen, Egyetem tér 1, Hungary 12Florida State University, Tallahassee, Florida 32306, USA 13Georgia State University, Atlanta, Georgia 30303, USA 14Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526, Japan 15Institute for High Energy Physics (IHEP), Protvino, Russia 16Iowa State University, Ames, Iowa 50011, USA 17Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia 18KAERI, Cyclotron Application Laboratory, Seoul, Korea 19Kangnung National University, Kangnung 210-702, Korea 20KEK, High Energy Accelerator Research Organization, Tsukuba-shi, Ibaraki-ken 305-0801, Japan 21KFKI Research Institute for Particle and Nuclear Physics (RMKI), H-1525 Budapest 114, P.O. Box 49, Hungary 22Korea University, Seoul, 136-701, Korea 23Russian Research Center “Kurchatov Institute,” Moscow, Russia 24Kyoto University, Kyoto 606-8502, Japan 25Laboratoire Leprince-Ringuet, Ecole Polytechnique, CNRS-IN2P3, Route de Saclay, F-91128, Palaiseau, France 26Lawrence Livermore National Laboratory, Livermore, California 94550, USA 27Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA 28LPC, Université Blaise Pascal, CNRS-IN2P3, Clermont-Fd, 63177 Aubiere Cedex, France 29Department of Physics, Lund University, Box 118, SE-221 00 Lund, Sweden 30Institut für Kernphysik, University of Muenster, D-48149 Muenster, Germany 31Myongji University, Yongin, Kyonggido 449-728, Korea 32Nagasaki Institute of Applied Science, Nagasaki-shi, Nagasaki 851-0193, Japan 33University of New Mexico, Albuquerque, New Mexico 87131, USA 34New Mexico State University, Las Cruces, New Mexico 88003, USA 35Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA 36IPN-Orsay, Universite Paris Sud, CNRS-IN2P3, BP1, F-91406, Orsay, France 37PNPI, Petersburg Nuclear Physics Institute, Gatchina, Russia 38RIKEN (The Institute of Physical and Chemical Research), Wako, Saitama 351-0198, Japan 39RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973-5000, USA 40St. Petersburg State Technical University, St. Petersburg, Russia 41Instituto de Física, Universidade de São Paulo, Caixa Postal 66318, São Paulo CEP05315-970, Brazil 42System Electronics Laboratory, Seoul National University, Seoul, Korea 43Chemistry Department, Stony Brook University, SUNY, Stony Brook, New York 11794-3400, USA 44Department of Physics and Astronomy, Stony Brook University, SUNY, Stony Brook, New York 11794, USA 45SUBATECH (Ecole des Mines de Nantes, CNRS-IN2P3, Université de Nantes), BP 20722-44307, Nantes, France 46University of Tennessee, Knoxville, Tennessee 37996, USA 47Department of Physics, Tokyo Institute of Technology, Tokyo, 152-8551, Japan 48Institute of Physics, University of Tsukuba, Tsukuba, Ibaraki 305, Japan 49Vanderbilt University, Nashville, Tennessee 37235, USA 50Waseda University, Advanced Research Institute for Science and Engineering, 17 Kikui-cho, Shinjuku-ku, Tokyo 162-0044, Japan 51Weizmann Institute, Rehovot 76100, Israel 52Yonsei University, IPAP, Seoul 120-749, Korea
Received 2 February 2005; published 8 April 2005
A measurement of direct photons in p+p collisions at √s=200 GeV is presented. A photon excess above background from π0→γ+γ, η→γ+γ and other decays is observed in the transverse momentum range 5.5<pT<7 GeV/c. The result is compared to a next-to-leading-order perturbative QCD calculation. Within errors, good agreement is found between the QCD calculation and the measured result.
© 2005 The American Physical Society
URL:
http://link.aps.org/doi/10.1103/PhysRevD.71.071102
DOI:
10.1103/PhysRevD.71.071102
*Deceased. †PHENIX spokesperson. Electronic address: zajc@nevis.columbia.edu
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