EVIDENCE FOR DECONFINEMENT FROM THE J/ψ SUPPRESSION PATTERN IN Pb-Pb COLLISIONS BY THE NA50 EXPERIMENT
- 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, and
- N. Willis
LIP, Lisbon, Portugal
also at UCEH, Universidade de Algarve, Faro, Portugal.
Università di Torino/INFN, Torino, Italy
IFA, Bucharest, Romania
Università di Torino/INFN, Torino, Italy
YerPhI, Yerevan, Armenia
LAPP, CNRS-IN2P3, Annecy-le- Vieux, France
LPC, Univ. Blaise Pascal and CNRS-IN2P3, Aubière, France
IPN, Univ. Claude Bernard Lyon-I and CNRS-IN2P3, Villeurbanne, France
Università di Torino/INFN, Torino, Italy
IFA, Bucharest, Romania
LIP, Lisbon, Portugal
also at IST, Universidade Técnica de Lisboa, Lisbon, Portugal.
LAPP, CNRS-IN2P3, Annecy-le- Vieux, France
IPN, Univ. Claude Bernard Lyon-I and CNRS-IN2P3, Villeurbanne, France
LPC, Univ. Blaise Pascal and CNRS-IN2P3, Aubière, France
LPC, Univ. Blaise Pascal and CNRS-IN2P3, Aubière, France
LPNHE, Ecole Polytechnique and CNRS-IN2P3, Palaiseau, France
LPC, Univ. Blaise Pascal and CNRS-IN2P3, Aubière, France
IPN, Univ. Claude Bernard Lyon-I and CNRS-IN2P3, Villeurbanne, France
Università di Torino/INFN, Torino, Italy
Università di Cagliari/INFN, Cagliari, Italy
LIP, Lisbon, Portugal
IPN, Univ. de Paris-Sud and CNRS-IN2P3, Orsay, France
LPNHE, Ecole Polytechnique and CNRS-IN2P3, Palaiseau, France
IFA, Bucharest, Romania
Università di Torino/INFN, Torino, Italy
Università di Cagliari/INFN, Cagliari, Italy
Università di Torino/INFN, Torino, Italy
Universitá del Piemonte Orientale, Alessandria and INFN-Torino, Italy.
LPC, Univ. Blaise Pascal and CNRS-IN2P3, Aubière, France
IFA, Bucharest, Romania
IPN, Univ. Claude Bernard Lyon-I and CNRS-IN2P3, Villeurbanne, France
IPN, Univ. Claude Bernard Lyon-I and CNRS-IN2P3, Villeurbanne, France
LPC, Univ. Blaise Pascal and CNRS-IN2P3, Aubière, France
LPC, Univ. Blaise Pascal and CNRS-IN2P3, Aubière, France
LPC, Univ. Blaise Pascal and CNRS-IN2P3, Aubière, France
Università di Torino/INFN, Torino, Italy
INR, Moscow, Russia
IPN, Univ. de Paris-Sud and CNRS-IN2P3, Orsay, France
Università di Torino/INFN, Torino, Italy
INR, Moscow, Russia
LPNHE, Ecole Polytechnique and CNRS-IN2P3, Palaiseau, France
YerPhI, Yerevan, Armenia
IPN, Univ. Claude Bernard Lyon-I and CNRS-IN2P3, Villeurbanne, France
INR, Moscow, Russia
IPN, Univ. Claude Bernard Lyon-I and CNRS-IN2P3, Villeurbanne, France
YerPhI, Yerevan, Armenia
YerPhI, Yerevan, Armenia
IPN, Univ. Claude Bernard Lyon-I and CNRS-IN2P3, Villeurbanne, France
Università di Torino/INFN, Torino, Italy
now at Faculty of Physics and Nuclear Techniques, University of Mining and Metallurgy, Cracow, Poland.
IPN, Univ. de Paris-Sud and CNRS-IN2P3, Orsay, France
INR, Moscow, Russia
LPNHE, Ecole Polytechnique and CNRS-IN2P3, Palaiseau, France
INR, Moscow, Russia
IPN, Univ. de Paris-Sud and CNRS-IN2P3, Orsay, France
CERN, Geneva, Switzerland
Università di Cagliari/INFN, Cagliari, Italy
IPN, Univ. de Paris-Sud and CNRS-IN2P3, Orsay, France
Università di Torino/INFN, Torino, Italy
Università di Torino/INFN, Torino, Italy
Università di Cagliari/INFN, Cagliari, Italy
YerPhI, Yerevan, Armenia
Università di Torino/INFN, Torino, Italy
Università di Torino/INFN, Torino, Italy
LPNHE, Ecole Polytechnique and CNRS-IN2P3, Palaiseau, France
Università di Torino/INFN, Torino, Italy
IPN, Univ. Claude Bernard Lyon-I and CNRS-IN2P3, Villeurbanne, France
Università di Torino/INFN, Torino, Italy
Università di Cagliari/INFN, Cagliari, Italy
LIP, Lisbon, Portugal
LIP, Lisbon, Portugal
also at IST, Universidade Técnica de Lisboa, Lisbon, Portugal.
Università di Torino/INFN, Torino, Italy
Universitá del Piemonte Orientale, Alessandria and INFN-Torino, Italy.
LIP, Lisbon, Portugal
Università di Torino/INFN, Torino, Italy
LPNHE, Ecole Polytechnique and CNRS-IN2P3, Palaiseau, France
CERN, Geneva, Switzerland
LPC, Univ. Blaise Pascal and CNRS-IN2P3, Aubière, France
Università di Torino/INFN, Torino, Italy
Università di Cagliari/INFN, Cagliari, Italy
LIP, Lisbon, Portugal
on leave of absence of YerPhI, Yerevan, Armenia.
LIP, Lisbon, Portugal
Università di Torino/INFN, Torino, Italy
Universitá del Piemonte Orientale, Alessandria and INFN-Torino, Italy.
Università di Torino/INFN, Torino, Italy
CERN, Geneva, Switzerland
also at IST, Universidade Técnica de Lisboa, Lisbon, Portugal.
IPN, Univ. de Paris-Sud and CNRS-IN2P3, Orsay, France
INR, Moscow, Russia
Università di Cagliari/INFN, Cagliari, Italy
Università di Torino/INFN, Torino, Italy
IPN, Univ. de Paris-Sud and CNRS-IN2P3, Orsay, France
IPN, Univ. de Paris-Sud and CNRS-IN2P3, Orsay, France
The NA50 experiment at CERN has found evidence for deconfinement in central Pb-Pb collisions at 158 A GeV/c at the CERN SPS. The anomalous (with respect to ordinary nuclear absorption) suppression of J/ψ has been observed in 1995 and 1996 data and has been confirmed with the 1998 data analysis, where a detailed study of the suppression pattern vs. centrality has been performed. NA50 results exclude present conventional hadronic models, while they find a natural explanation in the formation of a deconfined state of quarks and gluons.
