Abstract:Année de publication : 2000
The NA50 collaboration has recently observed that the J/$\psi$ production rate in Pb--Pb collisions decreases more rapidly as a function of the transverse energy for the most central collisions than for less central ones. We show that this phenomenon can be understood as an effect of transverse energy fluctuations in central collisions. A good fit of the data is obtained using a model which relates $J/\psi$ suppression to the local energy density. Furthermore, we argue that the successive meltings of charmonium resonances at different energy densities does not necessarily manifest itself as visible structures in the $E_T$ dependence of the $J/\psi$ suppression.