| Thème(s) : |
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Physique/Physique Nucléaire Expérimentale
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| Titre : |
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J/psi production in proton-nucleus collisions at 158 and 400 GeV |
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| Auteur : |
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R. Arnaldi, K. Banicz, J. Castor1, B. Chaurand2, W. M. Chen, C. Cicalo, A. Colla, P. Cortese, S. Damjanovic, A. David, A. De Falco, A. Devaux1, L. Ducroux3, H. En'yo, J. Fargeix1, A. Ferretti, M. Floris, A. Foerster, P. Force1, N. Guettet1, A. Guichard3, H. Gulkanian, J. M. Heuser, M. Keil, Z. Li, C. Lourenco, J. Lozano, F. Manso1, P. Martins, A. Masoni, A. Neves, H. Ohnishi, C. Oppedisano, P. Parracho, P. Pillot3, T. Poghosyan, G. Puddu, E. Radermacher, P. Ramalhete, P. Rosinsky, E. Scomparin, J. Seixas, S. Serci, R. Shahoyan, P. Sonderegger, H. J. Specht, R. Tieulent3, A. Uras, G. Usai, R. Veenhof, H. K. Woehri |
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| Laboratoire : |
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| Résumé : |
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The NA60 experiment has studied J/psi production in p-A collisions at 158 and 400 GeV, at the CERN SPS. Nuclear effects on the J/psi yield have been estimated from the A-dependence of the production cross section ratios sigma_{J/psi}^{A}/sigma_{J/psi}^{Be} (A=Al, Cu, In, W, Pb, U). We observe a significant nuclear suppression of the J/psi yield per N-N collision, with a larger effect at lower incident energy, and we compare this result with previous observations by fixed-target experiments. By studying, at the two energies, the dependence of nuclear effects on x_2, the fraction of nucleon momentum carried by the interacting parton from the target nucleus, we conclude that a combination of nuclear shadowing and break-up by target nucleons cannot be the only source of nuclear suppression of the J/psi. |
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| Collaboration/Projet : |
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NA60 |
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| Type de publication : |
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Articles dans des revues avec comité de lecture |
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Date de publication ou d'écriture : |
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2012 |
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| Nom du périodique : |
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| Physics Letters B (Phys. Lett. B) |
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Elsevier |
| ISSN |
0370-2693 |
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| Volume : |
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706 |
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| Page/Article : |
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263-267 |
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| Commentaire : |
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NA60 Collaboration, 5 pages, 3 figures, submitted to Phys. Rev. Lett. |
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