Author/Authors :
NA50 Collaboration، نويسنده , , Everton M.C. Abreu، نويسنده , , B. Alessandro، نويسنده , , C. Alexa، نويسنده , , R. Arnaldi، نويسنده , , M. Atayan، نويسنده , , C. Baglin، نويسنده , , A. Baldit، نويسنده , , M. Bedjidian، نويسنده , , S. Beolè، نويسنده , , V. Boldea، نويسنده , , P. Bordalo، نويسنده , , A. Bussière، نويسنده , , L. Capelli، نويسنده , , L. Casagrande، نويسنده , , J. Castor، نويسنده , , T. Chambon، نويسنده , , B. Chaurand، نويسنده , , I. Chevrot، نويسنده , , B. Cheynis، نويسنده , , et al.، نويسنده ,
Abstract :
The analysis of the data collected by the NA50 experiment in 1998, reported in this paper, extends and clarifies the pattern of the previously observed J/ψ anomalous suppression. This new measurement, besides providing a deeper understanding of the previous observations, reveals a steady significative decrease in the J/ψ production rate up to the most central Pb-Pb collisions. It clearly rules out the presently available conventional (hadronic) models of J/ψ suppression, which unanimously predict a saturation of the J/ψ rate for central Pb-Pb collisions. On the contrary and together with the sharp onset of the anomalous suppression previously reported, the new observation leads to a global production rate pattern which finds its natural explanation in the framework of the formation of a deconfined state of quarks and gluons.
