M. C. AbreuAlessandro, B.Alexa, C.Arnaldi, R.Atayan, M.Baglin, C.Baldit, A.Bedjidian, M.Beole, S.Boldea, V.Bordalo, P.Borges, G.Bussiere, A.Capelli, L.Castor, J.Castanier, C.Chaurand, B.Chevrot, ICheynis, BChiavassa, ECicalo, CClaudino, TComets, M. P.Constans, N.Constantinescu, S.Cortese, P.De Marco, N.De Falco, A.Dellacasa, G.Devaux, A.Dita, S.Drapier, O.Ducroux, L.Espagnon, B.Fargeix, J.Force, P.Grigorian, A. A.Grigorian, S.Grossiord, J. Y.Guber, F. F.Guichard, A.Gulkanyan, H.Hakobyan, R.Haroutunian, R.Idzik, M.Jouan, D.Karavitcheva, T. L.Kluberg, L.Kurepin, A. B.Le Bornec, Y.Lourenco, C.Macciotta, P.Mac Cormick, M.Marzari-Chiesa, A.Masera, M.Masoni, A.Monteno, M.Musso, A.Petiau, P.Piccotti, A.Pizzi, J. R.Prino, F.Puddu, G.Quintans, C.Ramos, S.Ramello, L.Mendes, P. R.Riccati, L.Romana, A.Santos, H.Saturnini, P.Scalas, E.Scomparin, E.Serci, S.Shahoyan, R.Sigaudo, F.Silva, S.Sitta, M.Sonderegger, P.Tarrago, X.Topilskaya, N. S.Usai, G. L.Vercellin, E.Villatte, L.Willis, N.2018-12-072018-12-072001-110370-2693http://hdl.handle.net/10400.1/11822The observation of an anomalous J/psi suppression in Pb-Pb collisions by the NA50 Collaboration can be considered as the most striking indication for the deconfinement of quarks and gluons at SPS energies. In this Letter, we determine the J/psi suppression pattern as a function of the forward hadronic energy E-ZDC measured in a Zero Degree Calorimeter (ZDC). The direct connection between EZDC and the geometry of the collision allows us to calculate, within a Glauber approach, the precise relation between the number of participant nucleons N-part and E-ZDC. Then, we check if the experimental data can be better explained by a sudden or a smooth onset of the anomalous J/psi suppression as a function of the number of participants. (C) 2001 Elsevier Science B.V. All rights reserved.engNucleus-nucleus collisionsPb-pb interactionsJ-psi-suppressionTransverse energy158 Gev/CCern-spsDeconfinementPatternjournal article10.1016/S0370-2693(01)01225-4