The dependence of the anomalous J/psi suppression on the number of participant nucleons

• Author(s): M. C. Abreu ; Alessandro, 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, I ; Cheynis, B ; Chiavassa, E ; Cicalo, C ; Claudino, T ; Comets, 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.
• Date: 2001
• Persistent ID: http://hdl.handle.net/10400.1/11822
• Origin: Sapientia - Universidade do Algarve
• Subject(s): Nucleus-nucleus collisions; Pb-pb interactions; J-psi-suppression; Transverse energy; 158 Gev/C; Cern-sps; Deconfinement; Pattern
• Document Type: Journal article
• Language: English
• Contributor(s): Sapientia

Description

The 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.