The NA50 experiment has measured, at the CERN SPS, the dimuon production in PbPb collisions at 158 GeV/c per nucleon, following the program of the previous NA38 and NA51 experiments, performed with proton and light ion beams. The J/Ψ production has been studied by NA50 as a function of the centrality of the collisions. The results of the analyses performed on three data samples, collected from 1995 to 1998, show that for peripheral collisions the J/Ψ cross section can be understood in terms of ordinary nuclear absorption, consistently with the extrapolation of previous measurements extending from p-p to S-U. On the contrary, the central events show an anomalous J/Ψ suppression, and the pattern of J/Ψ yield versus centrality features two discontinuities that cannot be described by conventional models based on hadronic scenarios. These results can be considered as a strong indication of the creation of a new state of matter in central PbPb collisions at the SPS.

Results from the NA50 experiment on J/Ψ suppression in Pb-Pb collisions at the CERN SPS

BEOLE', Stefania;CHIAVASSA, Emilio Luciano;GALLIO, Mauro;MASERA, Massimo;VERCELLIN, Ermanno;
2001-01-01

Abstract

The NA50 experiment has measured, at the CERN SPS, the dimuon production in PbPb collisions at 158 GeV/c per nucleon, following the program of the previous NA38 and NA51 experiments, performed with proton and light ion beams. The J/Ψ production has been studied by NA50 as a function of the centrality of the collisions. The results of the analyses performed on three data samples, collected from 1995 to 1998, show that for peripheral collisions the J/Ψ cross section can be understood in terms of ordinary nuclear absorption, consistently with the extrapolation of previous measurements extending from p-p to S-U. On the contrary, the central events show an anomalous J/Ψ suppression, and the pattern of J/Ψ yield versus centrality features two discontinuities that cannot be described by conventional models based on hadronic scenarios. These results can be considered as a strong indication of the creation of a new state of matter in central PbPb collisions at the SPS.
9th International Workshop on Multiparticle Production: New Frontiers in Soft Physics and Correlations on the Threshold of the New Millenium
Torino, Italy
12-17 Jun 2000.
92
43
54
M. Monteno;M.C. Abreu;B. Alessandro;C. Alexa;R. Arnaldi;M. Atayan;C. Baglin;A. Baldit;M. Bedjidian;S. Beolè;V. Boldea;P. Bordalo;A. Bussière;L. Capelli;L. Casagrande;J. Castor;T. Chambon;B. Chaurand;I. Chevrot;B. Cheynis;E. Chiavassa;C. Cicalò;T. Claudino;M.P. Comets;N. Constans;S. Constantinescu;N. De Marco;A. De Falco;G. Dellacasa;A. Devaux;S. Dita;O. Drapier;L. Ducroux;B. Espagnon;J. Fargeix;P. Force;M. Gallio;Y.K. Gavrilov;C. Gerschel;P. Giubellino;M.B. Golubeva;M. Gonin;A.A. Grigorian;J.Y. Grossiord;F.F. Guber;A. Guichard;H. Gulkanyan;R. Hakobyan;R. Haroutunian;M. Idzik;D. Jouan;T.L. Karavitcheva;L. Kluberg;A.B. Kurepin;Y. Le Bornec;C. Lourenço;P. Macciotta;M. Mac Cormick;A. Marzari-Chiesa;M. Masera;A. Masoni;S. Mehrabyan;M. Monteno;A. Musso;P. Petiau;A. Piccotti;J.R. Pizzi;F. Prino;G. Puddu;C. Quintans;S. Ramos;L. Ramello;P. Rato Mendes;L. Riccati;A. Romana;I. Ropotar;P. Saturnini;E. Scomparin;S. Serci;R. Shahoyan;S. Silva;M. Sitta;C. Soave;P. Sonderegger;X. Tarrago;N.S. Topilskaya;G.L. Usai;E. Vercellin;L. Villatte;N. Willis
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/106206
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