J/$\psi$ production in indium-indium collisions at SPS energies

Philippe Pillot (1) , R. Arnaldi , R. Avebeck , K. Banicz , J. Castor (2) , B. Chaurand (3) , C. Cicalo , A. Colla , P. Cortese , S. Damjanovic , A. David , A. de Falco , A. Devaux (2) , A. Drees , L. Ducroux (1) , H. En'Yo , A. Ferretti , M. Floris , P. Force (2) , N. Guettet (2) , A. Guichard (1) , H. Gulkanian , J. Heuser , M. Keil , L. Kluberg (3) , J. Lozano , C. Lourenço , F. Manso (2) , A. Masoni , P. Martins , A. Neves , H. Ohnishi , C. Oppedisano , P. Parracho , G. Puddu , E. Radermacher , P. Ramalhete , P. Rosinsky , E. Scomparin , J. Seixas , S. Serci , R. Shahoyan , P. Sonderegger , H.J. Specht , R. Tieulent (1) , G. Usai , R. Veenhof , H.K. Wörhri

1 IPNL - Institut de Physique Nucléaire de Lyon
2 LPC - Laboratoire de Physique Corpusculaire - Clermont-Ferrand
3 LLR - Laboratoire Leprince-Ringuet

The NA60 experiment collected data on dimuon production in indium-indium collisions at 158 GeV/c per incident nucleon, in year 2003, to contribute to the clarification of several questions raised by previous experiments studying high-energy heavy-ion physics at the CERN SPS in search of the quark gluon plasma. Among these previous results stands the observation, by NA50, that the production yield of J/psi mesons is suppressed in central Pb-Pb collisions beyond the normal nuclear absorption defined by proton-nucleus data. By comparing the centrality dependence of the suppression pattern between different colliding systems, S-U, Pb-Pb and In-In, we should be able to identify the corresponding scaling variable, and the physics mechanism driving the suppression. In this paper, we will present the ratio of J/psi and Drell-Yan production cross-sections in indium-indium collisions, in three centrality bins, and how these values compare to previous measurements. We will also present a study of the transverse momentum distributions of the J/psi mesons, in seven centrality bins.

Domaines: Physique des Hautes Energies - Expérience [hep-ex]

Philippe Pillot, R. Arnaldi, R. Avebeck, K. Banicz, J. Castor, et al.. J/$\psi$ production in indium-indium collisions at SPS energies. QCD@Work 2005 International Workshop on Quantum Chromodynamics: Theory and Experiment, Jun 2005, Conversano, Bari, Italy. pp.279-285, ⟨10.1063/1.2163775⟩. ⟨in2p3-00025240⟩