Direct photons in WA98

A measurement of direct photon production in /sup 208/Pb+/sup 208/Pb collisions at 158 A GeV has been carried out in the CERN WA98 experiment. The invariant yield of direct photons was extracted as a function of transverse momentum in the interval 0.5<P/sub T/<3.3 GeV /c for, peripheral, and 0...

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Detalles Bibliográficos
Autores principales: Aggarwal, M M, Agnihotri, A, Ahammed, Z, Angelis, Aris L S, Antonenko, V G, Arefev, V, Astakhov, V A, Avdeichikov, V, Awes, T C, Baba, P V K S, Badyal, S K, Barlag, C, Bathe, S, Batyunya, B, Bernier, T, Bhalla, K B, Bhatia, V S, Blume, C, Bock, R, Bohne, E M, Böröcz, Z K, Bucher, D, Buijs, A, Büsching, H, Carlén, L, Chalyshev, V, Chattopadhyay, S, Cherbachev, R, Chujo, T, Claussen, A, Das, A C, Decowski, M P, Delagrange, H, Dzhordzhadze, V, Dönni, P, Dubovik, I, Dutt, S, Dutta-Majumdar, M R, El-Chenawi, K F, Eliseev, S, Enosawa, K, Foka, P Y, Fokin, S L, Ganti, M S, Garpman, S, Gavrishchuk, O P, Geurts, F J M, Ghosh, T K, Glasow, R, Gupta, S K, Guskov, B, Gustafsson, Hans Åke, Gutbrod, H H, Higuchi, R, Hrivnacova, I, Ippolitov, M S, Kalechofsky, H, Kamermans, R, Kampert, K H, Karadzhev, K, Karpio, K, Kato, S, Kees, S, Klein-Bösing, C, Knoche, S, Kolb, B W, Kosarev, I G, Kucheryaev, I, Krümpel, T, Kugler, A, Kulinich, P A, Kurata, M, Kurita, K, Kuzmin, N A, Langbein, I, Lee, Y Y, Löhner, H, Luquin, Lionel, Mahapatra, D P, Man'ko, V I, Martin, M, Martínez, G, Maksimov, A, Mgebrishvili, G, Miake, Y, Mir, M F, Mishra, G C, Miyamoto, Y, Mohanty, B, Morrison, D, Mukhopadhyay, D S, Naef, H, Nandi, B K, Nayak, S K, Nayak, T K, Neumaier, S, Nyanin, A, Nikitin, V A, Nikolaev, S, Nilsson, P O, Nishimura, S, Nomokonov, V P, Nystrand, J, Obenshain, F E, Oskarsson, A, Otterlund, I, Pachr, M, Pavlyuk, S, Peitzmann, Thomas, Petracek, V, Pinganaud, W, Plasil, F, Von Poblotzki, U, Purschke, M L, Rak, J, Raniwala, R, Raniwala, S, Ramamurthy, V S, Rao, N K, Retière, F, Reygers, K, Roland, G, Rosselet, L, Rufanov, I A, Roy, C, Rubio, J M, Sako, H, Sambyal, S S, Santo, R, Sato, S, Schlagheck, H, Schmidt, H R, Schutz, Y, Shabratova, G, Shah, T H, Sibiryak, Yu, Siemiarczuk, T, Silvermyr, D, Sinha, B C, Slavin, N V, Söderström, K, Solomey, Nickolas, Sood, G, Sørensen, S P, Stankus, P, Stefanek, G, Steinberg, P, Stenlund, E, Stüken, D, Sumbera, M, Svensson, S, Trivedi, M D, Tsvetkov, A A, Tykarski, L, Urbahn, J, Van den Pijll, E C, van Eijndhoven, N, van Nieuwenhuizen, G J, Vinogradov, A, Viyogi, Y P, Vodopyanov, A S, Vörös, S, Wyslouch, B, Yagi, K, Yokota, Y, Young, G R
Lenguaje:eng
Publicado: 2002
Materias:
Particle Physics - Experiment
Acceso en línea:https://dx.doi.org/10.1016/S0375-9474(01)01357-4
http://cds.cern.ch/record/544437
Descripción
Sumario:A measurement of direct photon production in /sup 208/Pb+/sup 208/Pb collisions at 158 A GeV has been carried out in the CERN WA98 experiment. The invariant yield of direct photons was extracted as a function of transverse momentum in the interval 0.5<P/sub T/<3.3 GeV /c for, peripheral, and 0.5<P/sub T/<4.0 GeV/c for central collisions. The direct photon yield was extracted on a statistical basis as the difference between the measured inclusive spectrum of photons; and the calculated spectrum of photons which result from all hadrons with significant radiative decay contributions. While no direct photon excess was observed for the peripheral event sample, a, significant direct photon signal, compared to statistical and systematical errors, was seen in central collisions at P/sub T/>1.5 GeV/c. the result constitutes the first observation of direct photons in ultrarelativistic heavy-ion collisions. (19 refs).

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