Author: "A.A. Grigorian" / Database: OpenAIRE - Searchworks@Jio Institute Digital Library Search Results

Author: J. Seixas, A. David, Markus Keil, S. Damjanović, Brigitte Cheynis, Jean-Yves Grossiord, Raphael Noel Tieulent, N. Guettet, R. Shahoyan, Laurent Ducroux, Jan Buytaert, P. Force, R. Veenhof, N. De Marco, Chiara Oppedisano, A. Colla, E. Radermacher, Franck Manso, H. En'yo, Wen-Chang Chen, P. Pillot, K. Banicz, Hermine Katharina Wöhri, Alessandro Ferretti, P. Rosinsky, H. J. Specht, A. Neves, B. Chaurand, J. Lozano, Pietro Cortese, Hiroaki Ohnishi, S. Serci, Enrico Scomparin, A. Devaux, A. Drees, J. Castor, G. L. Usai, H. Gulkanian, P. Sonderegger, Z. Li, Carlos Lourenco, Pcf Parracho, L. Kluberg, J. M. Heuser, E. Tveiten, Corrado Cicalo, H. Vardanyan, A. Guichard, K. Borer, P. Ramalhete, Roberta Arnaldi, A. De Falco, A.A. Grigorian, Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), D. Adamova, A. Kugler, P. Tlusty, NA60, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Muon, Meson production, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Nuclear Theory, 7. Clean energy, 01 natural sciences, Vertex (geometry), law.invention, Nuclear physics, Telescope, Muon spectrometer, law, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Physics::Accelerator Physics, High Energy Physics::Experiment, Heavy ion, Nuclear Experiment, 010306 general physics
Abstract: NA60; The NA60 experiment at the CERN SPS studies dimuon production in proton and heavy ion collisions. Its silicon pixel vertex telescope allows tracking of muon pairs in the vertex region, complementing the information from the muon spectrometer, and improving the mass resolution and signal-to-noise ratio. First results from the In-In data taking are shown for the light resonances and the J/$\psi$ meson production.
Published: 2005
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9. Charged particle multiplicity in Pb-Pb collisions from the NA50 experiment

Author: R. Haroutunian, Roberta Arnaldi, Sanda Dita, D. Jouan, C. Quintans, M. Atayan, G. Borges, T. Claudino, T.L. Karavitcheva, B. Espagnon, P. Petiau, A. Baldit, Paolo Giubellino, Pietro Cortese, Stefania Beole, Enrico Scomparin, Y.K. Gavrilov, M. Gonin, Serban Constantinescu, X. Tarrago, P. Sonderegger, Mario Sitta, C. Castanier, P. Force, Marek Idzik, O. Drapier, H.R. Gulkanyan, F.F. Guber, Alexey Kurepin, Carlos Lourenco, L. Kluberg, N.S. Topilskaya, P. Saturnini, M. Mac Cormick, Mauro Gallio, V. Boldea, L. Riccati, A. Musso, G. L. Usai, C. Baglin, P. Rato Mendes, S. Serci, Ermanno Vercellin, Luciano Ramello, G. Puddu, J.-R. Pizzi, Bruno Alessandro, B. Chaurand, L. Capelli, N. Willis, A. Devaux, C. Gerschel, F Prino, W.L. Prado da Silva, F. Sigaudo, J.-Y. Grossiord, A. Piccotti, T. Wu, A. Bussiere, M. P. Comets, Enrico Scalas, A. Defalco, A.A. Grigorian, G. Dellacasa, Alberto Masoni, A. Romana, João Cruz, P. Macciotta, Calin Alexa, Helena Santos, M.B. Golubeva, M. Bedjidian, A. Guichard, F. Prino, S. Grigorian, J. Fargeix, A. Marzari-Chiesa, Massimo Masera, P. Bordalo, S. Ramos, R Hokobyan, Brigitte Cheynis, E. Chiavassa, Ruben Shahoyan, N DeMarco, Marco Monteno, Y. Le Bornec, J. Castor, S. Borenstein, L. Villatte, Corrado Cicalo, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), NA50, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: Physics, History, Large Hadron Collider, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Nuclear Theory, 01 natural sciences, 7. Clean energy, Charged particle, Computer Science Applications, Education, Nuclear physics, Transverse plane, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Impact parameter, Multiplicity (chemistry), Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Particle density, Charged particle beam
Abstract: NA50; Angular distributions of charged particles produced in Pb-Pb collisions at the CERN SPS have been measured by the NA50 experiment. Measurements have been performed with a silicon microstrip detector at two different beam energies (40 and 158 GeV/nucleon) and over a wide impact parameter (centrality) range. The centrality of the collision has been evaluated both by neutral transverse energy released in the interaction and by spectator nucleons energy (zero degree energy). The charged particle density at midrapidity shows a linear dependence on the number of participating nucleons at both beam energies. The particle density per participant pair and its $\sqrt{S}$ dependence are also studied.
Published: 2005
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10. The production of , and mesons in p-, d-, S- and Pb-induced reactions at the CERN SPS

Author: Corrado Cicalo, X. Tarrago, C. Castanier, Mario Sitta, Sergio Serci, H.R. Gulkanyan, E. Vercellin, M. Bedjidian, Stefania Beole, W.L. Prado da Silva, F. Sigaudo, N DeMarco, M. Gallio, S. Grigorian, F.F. Guber, P. Force, S. Borenstein, Luciano Ramello, R. Haroutunian, A. Guichard, L. Villatte, Pietro Cortese, Massimo Masera, Y.K. Gavrilov, J. Fargeix, M. Mac Cormick, Enrico Scalas, A. Defalco, A.A. Grigorian, A. Marzari-Chiesa, Marco Monteno, Alexey Kurepin, Y. Le Bornec, E. Chiavassa, Ruben Shahoyan, João Cruz, A. Musso, A. Masoni, F Prino, G. Dellacasa, A. Romana, P. Rato Mendes, Roberta Arnaldi, G. Puddu, Carlos Lourenco, M. P. Comets, Helena Santos, Calin Alexa, G. L. Usai, P. Bordalo, B. Chaurand, L. Kluberg, N.S. Topilskaya, J. Castor, R. Hakobyan, O. Drapier, C. Gerschel, S. Ramos, G. Borges, T.L. Karavitcheva, A. Baldit, C. Baglin, Serban Constantinescu, B. Espagnon, C. Quintans, M. Atayan, Brigitte Cheynis, Bruno Alessandro, J.-R. Pizzi, Enrico Scomparin, L. Riccati, M. Gonin, T. Claudino, J.-Y. Grossiord, P. Macciotta, Marek Idzik, P. Petiau, P. Sonderegger, T. Wu, Sanda Dita, D. Jouan, V. Boldea, L. Capelli, N. Willis, A. Devaux, P. Saturnini, A. Piccotti, A. Bussiere, M.B. Golubeva, and Paolo Giubellino
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Muon, Meson, Proton, 010308 nuclear & particles physics, 7. Clean energy, 01 natural sciences, Omega, Nuclear physics, Pair production, Deuterium, 0103 physical sciences, 010306 general physics
Abstract: From proton, deuteron, S- and Pb-induced reactions, experiments NA38 and NA50 have measured muon pair production with various targets. In particular, the production rates of the , ω and ρ mesons have been simultaneously extracted and compared. Preliminary partial results of the most recent Pb–Pb measurement done in year 2000 by NA50 are presented here. They are also included in the comparison with the results obtained with lighter interacting nuclei.
Published: 2003
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11. Pseudorapidity distributions of charged particles in Pb-Pb collisions at super proton synchrotron energies from the NA50 experiment

Author: T. Claudino, J.-Y. Grossiord, Mario Sitta, Paolo Giubellino, Y.K. Gavrilov, Sergio Serci, M. Idzik, B. Espagnon, X. Tarrago, C. Castanier, Bruno Alessandro, Alexey Kurepin, A. Piccotti, G. Dellacasa, A. Baldit, Serban Constantinescu, Helena Santos, M. Masera, M. P. Comets, F. Prino, M. Mac Cormick, L. Villatte, Roberta Arnaldi, A.A. Grigorian, L. Riccati, A. Romana, Corrado Cicalo, I. Chevrot, A. De Falco, P. Bordalo, R. Hakobyan, J. Fargeix, Ermanno Vercellin, A. Bussiere, N. De Marco, S. Ramos, Stefania Beole, P. Saturnini, W.L. Prado da Silva, Calin Alexa, F. Sigaudo, O. Drapier, R. Haroutunian, M. C. Abreu, Giulio Usai, N. Willis, A. Masoni, M.B. Golubeva, A. Devaux, P. Force, G. Puddu, A. Guichard, C. Quintans, N. Constans, M. Atayan, Enrico Scalas, S. Silva, M. Bedjidian, Brigitte Cheynis, Pietro Cortese, E. Scomparin, G. Borges, T.L. Karavitcheva, S. Grigorian, P. Petiau, Carlos Lourenco, L. Kluberg, N.S. Topilskaya, P. Sonderegger, J.-R. Pizzi, Y. Le Bornee, Marek Idzik, A. Musso, Sanda Dita, D. Jouan, M. Gonin, H.R. Gulkanyan, Mauro Gallio, V. Boldea, L. Capelli, F.F. Guber, Luciano Ramello, P. Rato Mendes, B. Chaurand, C. Gerschel, Laurent Ducroux, C. Baglin, P. Macciotta, E. Chiavassa, Ruben Shahoyan, A. Marzari-Chiesa, Marco Monteno, and J. Castor
Subjects: Physics, Particle physics, Large Hadron Collider, Nuclear Theory, General Physics and Astronomy, Super Proton Synchrotron, Charged particle, Nuclear physics, Pseudorapidity, High Energy Physics::Experiment, Multiplicity (chemistry), Impact parameter, Nuclear Experiment, Nucleon
Abstract: We present the measurements of charged particle pseudorapidity distributions dNch/dη performed by the NA50 experiment in Pb-Pb collisions at the CERN SPS. Measurements were done at incident energies of 40 GeV (√s = 8.77 GeV) and 158 GeV (√s = 17.3 GeV) per nucleon over a broad impact parameter range. The multiplicity distributions are studied as a function of centrality using the number of participating nucleons(N part ), or the number of binary nucleon-nucleon collisions (Ncoll). Their values at midrapidity exhibit a linear scaling withN part at both energies. Particle yield increases approximately by a factor of 2 betweeny √s = 8.77 GeV and √s = 17.3 GeV.
Published: 2003
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12. Results on leptonic probes from NA50

Author: R. Haroutunian, M. Mac Cormick, Pietro Cortese, A. Bussiere, N. Willis, G. Puddu, S. Dita, E. Vercellin, J.Y. Grossiord, Yu.K. Gavrilov, A. B. Kurepin, S. Constantinescu, S. Ramos, A. Romana, X. Tarrago, Paolo Giubellino, A. Masoni, C. Castanier, B. Cheynis, R. Arnaldi, M. Bedjidian, O. Drapier, Mario Sitta, S. Grigorian, S. Borenstein, C. Cicalò, F.F. Guber, Enrico Scomparin, G. Borges, T.L. Karavitcheva, C. Alexa, L. Villatte, Y. Le Bornec, V. Boldea, P. Rato Mendes, W. L. Prado Da Silva, A. Musso, P. Bordalo, B. Espagnon, A. Marzari-Chiesa, C. Lourenço, M. Gallio, Marco Monteno, C. Quintans, M. Atayan, R. Hakobyan, L. Ramello, M. Gonin, M. P. Comets, L. Capelli, B. Chaurand, M. Masera, S. Beolè, M.B. Golubeva, A. Guichard, J.-R. Pizzi, C. Gerschel, P. Force, P. Sonderegger, J. Castor, L. Riccatoi, P. Petiau, G. Dellacasa, H. Gulkanyan, Helena Santos, E. Chiavassa, Marek Idzik, F. Sigaudo, Bruno Alessandro, C. Baglin, S. Serci, N DeMarco, G.L. Usai, L. Kluberg, N.S. Topilskaya, Enrico Scalas, A. Defalco, P. Macciotta, A. Baldit, João Cruz, J. Fargeix, A. Piccotti, A.A. Grigorian, F. Prino, D. Jouan, P. Saturnini, A. Devaux, T. Wu, R. Shahoyan, and T. Claudino
Subjects: Physics, Nuclear and High Energy Physics, Stereochemistry
Abstract: L. Ramello’) for the NA50 Collaboration: B. Alessandro”), C. Alexa4), R. Arnaldi”), M. Atayanr3), C. Baglin2), A. Baldit3), M. Bedjidian12), S. Beolk”), V. Boldea4), P. Bordalo?+), S.R. Borensteinr”lb), G. Borges 7), A. Bussiitre2), L. Cape111 ‘ 2), C. Castanier3), J. Castor3), B. Chaurand’“), B. Cheynis rz), E. Chiavassa”), C. Cicalb5), T. Claudino7) M P Cometsg), . . S. Constantinescu4), P. Cortese’), J. Cruz’I), A. DeFalco”): N. DeMarco’l), G. Dellacasa’), A. Devaux3), S. Dita4), 0. Drapier’O), B. Espagnon3), J. Fargeix3), P. Force3), M. Gallio”), Y.K. Gavrilovs), C. Gerschelg), P. Giubellino”“), MB. Golubeva@, M. Gonin”), A.A. Grigorian13), S. Grigorian13), J.Y. Grossiord12), F.F. Guber’), A. Guichard12), H. Gulkanyani3), R. Hakobyan13), R. Haroutunian12), M. Idzik”Td), D. Jouan’), T.L. Karavitcheva 8), L. Kluberg “1, A.B. Kurepin 8), Y. Le Bornecg), C. Lourenco 6), P. Macciotta5), M. Mac Cormickg), A. Marzari-Chiesa’*), M. Maserall), A. Mssoni 5), M. Monteno”), A. Mussoll), P. Petiaul”), A. Piccotti”), J R Pizzi12) . . W L Prado da Silva’r”) F. Prino L. Ramello’f, S. . . 11), G. Puddu5), C. Quintans’), Ramos 7+), P. Rato Mendes7), L. Riccati *l), A. RomanalO), H. Santos’) P. Saturnini3), E. Scalas’) E. Scomparin 11), S. Serci5), R. Shahoyan7yf), F. Sigaudo”), M. Sitta’), P. Sonderegge#+), X. Tarragog), N.S. Topilskaya’), G.L. Usai51, E. Vercellin”), L. Villatteg), N. Willisg), T. Wug).
Published: 2003
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13. $\phi$ and $\rho$ $plus$ $\omega$ vector-mesons produced in lead-induced collisions

Author: P. Rato Mendes, B. Chaurand, S R Borenstein, Mauro Gallio, V. Boldea, C. Gerschel, Mario Sitta, H.R. Gulkanyan, J. Fargeix, Sergio Serci, M. P. Comets, A. Masoni, Ermanno Vercellin, Enrico Scomparin, M. Gonin, S. Ramos, A. Baldit, A. Romana, Y Le Bornec, Calin Alexa, L. Ramello, W.L. Prado da Silva, P. Petiau, Roberta Arnaldi, F. Sigaudo, G. Puddu, P. Sonderegger, Paolo Giubellino, Bruno Alessandro, L. Riccati, N. De Marco, E Scalas, A. De Falco, Sanda Dita, D. Jouan, C Castanier, A. Bussiere, G. Borges, M.C. Abreu, C. Quintans, A. Guichard, T.L. Karavitcheva, M. Atayan, P. Saturnini, Serban Constantinescu, N. Constans, Y.K. Gavrilov, B. Espagnon, M.B. Golubeva, A. Piccotti, J.-R. Pizzi, Alexey Kurepin, A.A. Grigorian, L. Villatte, João Cruz, S. Silva, F. Prino, Jean-Yves Grossiord, M Bedjidian, N. Willis, L Capelli, G. L. Usai, A. Musso, Brigitte Cheynis, Pietro Cortese, Carlos Lourenco, L. Kluberg, N.S. Topilskaya, Stefania Beole, A. Marzari-Chiesa, Marco Monteno, P. Force, M. Mac Cormick, J. Castor, Corrado Cicalo, S. Grigorian, X. Tarrago, T. Claudino, Massimo Masera, E. Chiavassa, Ruben Shahoyan, C. Baglin, R Haroutunian, G. Dellacasa, Helena Santos, P. Macciotta, O Drapier, P. Bordalo, R. Hakobyan, A. Devaux, Marek Idzik, and F.F. Guber
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Proton, Meson, Strangeness production, Inverse, Heavy ion, Nuclear Experiment, Omega, Scaling, Ion
Abstract: The experiment NA50 studies the strangeness production by means of the BRμμσ/(BRρμμσρ + BRωμμσω) cross-sections ratio in relativistic heavy ion collisions with respect to proton and light ion collisions. New results for Pb+Pb interactions at 158 A GeV/c are presented (1998 data) and analysed with a different method. The BRμμσ/(BRρμμσρ + BRωμμσω) ratio shows an increase with the number of participants, in agreement with previous results. The inverse slope parameter extracted from the MT universal scaling is also studied.
Published: 2002
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14. Strangeness measurements in NA50 experiment with Pb projectiles

Author: X. Tarrago, Mario Sitta, A. Romana, Sergio Serci, Calin Alexa, A. Bussiere, Mauro Gallio, V. Boldea, O. Drapier, J. Astruc, J.-Y. Grossiord, L. Riccati, Ermanno Vercellin, W.L. Prado da Silva, N. Constans, H.R. Gulkanyan, Paolo Giubellino, C. Soave, A. Piccotti, M. Bedjidian, I. Chevrot, L. Capelli, A. Masoni, P. Petiau, B. Espagnon, S. Silva, M.B. Golubeva, F. Ohlsson-Malek, T. Chambon, N. Willis, A. Marzari-Chiesa, A. Devaux, S. Mehrabyan, A.A. Grigorian, J. Fargeix, S. Mourgues, Roberta Arnaldi, P. Sonderegger, Marco Monteno, Laurent Ducroux, J.-R. Pizzi, Marek Idzik, João Cruz, Massimo Masera, Brigitte Cheynis, S. Ramos, L. Casagrande, Enrico Scomparin, S. Filippov, Y. Le Bornec, M. Gonin, E. Chiavassa, Bruno Alessandro, I. Ropotar, A. Guichard, F.F. Guber, G. L. Usai, B. Chaurand, Ruben Shahoyan, Luciano Ramello, M.C. Abreu, P. Bordalo, C. Gerschel, R. Hakobyan, T.L. Karavitcheva, A. De Falco, N. De Marco, G. Dellacasa, R. Haroutunian, P. Saturnini, Serban Constantinescu, A. Musso, F. Bellaiche, J. Castor, François Fleuret, Corrado Cicalo, C. Baglin, Y.K. Gavrilov, P. Rato-Mendes, P. Macciotta, Carlos Lourenco, Alexey Kurepin, L. Kluberg, L. Villatte, N.S. Topilskaya, C. Racca, V. Caponi, C. Quintans, M. Atayan, M. P. Comets, A. Baldit, Sanda Dita, D. Jouan, G. Puddu, S. Beole, M. Mac Cormick, and P. Force
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, Transverse plane, Particle physics, Projectile, Transverse mass, Strangeness, Low Mass
Abstract: Low mass dimuons production has been studied in Pb-Pb collisions at 158 GeV/A . φ, ρ and ω contributions are extracted in different transverse mass and transverse energy domains. Preliminary results of the 1996 run display an increase of the φ/(ρ+ω) ratio, coming from an increase of the φ. Cross sections are presented and temperatures extracted.
Published: 2000
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15. Charmonium production in Pb−Pb collisions

Author: Corrado Cicalo, P. Petiau, R. Haroutunian, P. Sonderegger, Mario Sitta, Sergio Serci, S. Filippov, P. Bordalo, A. Marzari-Chiesa, B. Espagnon, R. Hakobyan, M. Mac Cormick, Marco Monteno, Y. Le Bornec, Bruno Alessandro, I. Ropotar, Paolo Giubellino, J. Castor, Stefania Beole, A. Masoni, M. P. Comets, P. Force, M.C. Abreu, Ermanno Vercellin, F. Bellaiche, T.L. Karavitcheva, Luciano Ramello, Marek Idzik, L. Villatte, J. Astruc, F. Guber, N. Willis, François Fleuret, A. Devaux, C. Racca, W.L. Prado da Silva, A.A. Grigorian, Carlos Lourenco, L. Kluberg, N.S. Topilskaya, A. Romana, Massimo Masera, Sanda Dita, S. Silva, J.-R. Pizzi, D. Jouan, T. Chambon, X. Tarrago, G. Dellacasa, Brigitte Cheynis, Calin Alexa, E. Chiavassa, Ruben Shahoyan, V. Caponi, A. Piccotti, C. Baglin, C. Quintans, M. Atayan, A. Baldit, P. Rato-Mendes, Serban Constantinescu, M. Bedjidian, H.R. Gulkanyan, L. Riccati, C. Soave, I. Chevrot, O. Drapier, A. Musso, P. Macciotta, A. De Falco, S. Ramos, S. Mehrabyan, P. Saturnini, A. B. Kurepin, Mauro Gallio, V. Boldea, Enrico Scomparin, M. B. Golubeva, M. Gonin, L. Capelli, S. Mourgues, Roberta Arnaldi, J.-Y. Grossiord, A. Bussiere, Laurent Ducroux, Nora De Marco, Y.K. Gavrilov, B. Chaurand, F. Ohlsson-Malek, C. Gerschel, L. Casagrande, A. Guichard, N. De Marco, G. L. Usai, J. Fargeix, N. Constans, João Cruz, and G. Puddu
Subjects: Physics, Nuclear physics, Nuclear and High Energy Physics, Particle model, Quarkonium
Published: 2000
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16. φ, ρ and ω production in Pb-Pb collisions at 158 GeV/c2 per nucleon

Author: H.R. Gulkanyan, C. Soave, Paolo Giubellino, A. Masoni, B. Espagnon, S. Silva, C. Baglin, J. Fargeix, S. Mehrabyan, I. Ropotar, Brigitte Cheynis, A. Musso, P. Petiau, L. Villatte, J.-R. Pizzi, W.L. Prado da Silva, Mario Sitta, Nicole Willis, Bruno Alessandro, P. Rato-Mendes, A. Guichard, P. Sonderegger, T. Chambon, Sergio Serci, R. Haroutunian, Enrico Scomparin, C. Racca, M. Gallio, S.N. Filippov, M. Gonin, M. P. Comets, A. Marzari-Chiesa, Y.K. Gavrilov, X. Tarrago, F. Ohlsson-Malek, Marco Monteno, Y. Le Bornec, J.-Y. Grossiord, F. Bellaiche, N. Constans, Alexey Kurepin, A. Romana, F.F. Guber, Calin Alexa, G. L. Usai, A. Baldit, Serban Constantinescu, J. Astruc, P. Macciotta, J. Castor, S. Mourgues, Roberta Arnaldi, L. Casagrande, Corrado Cicalo, V. Boldea, T.L. Karavitcheva, L. Ramello, A. Bussiere, N. De Marco, B. Chaurand, A.A. Grigorian, O. Drapier, C. Gerschel, A. Devaux, M.C. Abreau, E. Vercellin, M. Bedjidian, François Fleuret, M.B. Golubeva, L. Capelli, Massimo Masera, João Cruz, Sanda Dita, A. De Falco, D. Jouan, Laurent Ducroux, E. Chiavassa, Ruben Shahoyan, Carlos Lourenco, L. Kluberg, P. Saturnini, N.S. Topilskaya, V. Caponi, A. Piccotti, C. Quintans, M. Atayan, G. Puddu, Stefania Beole, P. Force, M. Mac Cormick, R. Hakobyan, Marek Idzik, S. Ramos, G. Dellacasa, L. Riccati, and I. Chevrot
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, Nucleon
Published: 1999
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17. Fission of lead projectiles in Pb-nucleus collisions at the SPS

Author: F. Ohlsson-Malek, Ermanno Vercellin, Stefania Beole, W.L. Prado da Silva, P. Force, H.R. Gulkanyan, C. Soave, G. Dellacasa, Enrico Scalas, G. L. Usai, B. Chaurand, S. Mehrabyan, A. B. Kurepin, F.F. Guber, J. Astruc, C. Gerschel, A. Guichard, M. Mac Cormick, L. Villatte, T.L. Karavitcheva, L. Riccati, Calin Alexa, Paolo Giubellino, I. Ropotar, I. Chevrot, M. Bedjidian, O. Drapier, C. Racca, G. Puddu, Mario Sitta, R. Haroutunian, Corrado Cicalo, J. Fargeix, A. Bussiere, Sergio Serci, S. Ramos, A. Musso, Laurent Ducroux, B. Espagnon, P. Petiau, A. Masoni, Alessandro Ferretti, Y.K. Gavrilov, Enrico Scomparin, Mauro Gallio, M. Gonin, M.B. Golubeva, V. Boldea, A. Romana, P. Sonderegger, L. Capelli, A. Marzari-Chiesa, Marco Monteno, Sanda Dita, D. Jouan, Y. Le Bornec, J. Castor, S. Silva, L. Casagrande, Brigitte Cheynis, N. De Marco, N. Constans, P. Bordalo, R. Hakobyan, N. Willis, A. Devaux, Marek Idzik, A. De Falco, P. Saturnini, A. Piccotti, J.-Y. Grossiord, M.C. Abreu, S. Mourgues, Roberta Arnaldi, S.N. Filippov, João Cruz, A.A. Grigorian, A. Baldit, Serban Constantinescu, X. Tarrago, Bruno Alessandro, Pietro Cortese, Carlos Lourenco, L. Kluberg, N.S. Topilskaya, J.-R. Pizzi, L. Ramello, T. Chambon, V. Caponi, C. Quintans, M. Atayan, M. P. Comets, F. Bellaiche, C. Baglin, P. Rato-Mendes, P. Macciotta, Massimo Masera, E. Chiavassa, Ruben Shahoyan, Chiara Oppedisano, and François Fleuret
Subjects: Nuclear physics, Physics, Nuclear and High Energy Physics, Particle physics, Lead (geology), medicine.anatomical_structure, Fission, Projectile, medicine, Nucleus
Published: 1999
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18. F, ϱ and ω production in collisions induced by deuteron and heavy ions around 200 GeV per nucleon

Author: A. De Falco, Rachid Mazini, Y. Le Bornec, O. Drapier, C. Barrière, H.R. Gulkanyan, Ermanno Vercellin, C. Soave, P. Saturnini, M. Mac Cormick, S. Silva, P. Petiau, Massimo Masera, E. Chiavassa, Ruben Shahoyan, W.L. Prado da Silva, R. Haroutunian, V. Capony, F.F. Guber, Paolo Giubellino, P. Sonderegger, G. Puddu, N. Willis, A. Devaux, M. P. Comets, T. Chambon, J. Castor, S. Mehrabyan, Brigitte Cheynis, S. Filippov, J.M. Gago, A. Bussiere, J. Guimara˜es, Petar Temnikov, P. Gorodestky, L. Fredj, X. Tarrago, J. Fargeix, A. Marzari-Chiesa, L. Casagrande, S. Beole, J. Astruc, S. Sartori, M.C. Abreu, B. Chaurand, S. Papillon, J.-Y. Grossiord, S. Serci, T.L. Karavitcheva, Y.K. Gavrilov, A. Baldit, S. Ramos, A. Romana, J.P. Guillaud, N. De Marco, R. Ferreira, C. Gerschel, C. Racca, Calin Alexa, Corrado Cicalo, B. Espagnon, Alexey Kurepin, P. Force, M. Bedjidian, A. Piccotti, Alberto Masoni, G. Dellacasa, R. Kossakowski, D. Jouan, S. Mourgues, Roberta Arnaldi, Enrico Scomparin, B. Grosdidier, M. Gonin, M.B. Golubeva, L. Riccati, I. Chevrot, T. Monteiro, R. Mandry, D. Lazic, F. Bellaiche, L. Ramello, L. Luquin, G. L. Usai, G. Landaud, Claude Charlot, R.A. Salmeron, A. Guichard, F. Ohlsson-Malek, C. Vale, C. Quintans, M. Atayan, C. Baglin, P. Rato-Mendes, Philippe Busson, P. Macciotta, Joao Varela, Bruno Alessandro, Marek Idzik, J.-R. Pizzi, François Fleuret, P. Bordalo, R. Hakobyan, João Cruz, Didier Contardo, B. Ronceux, Carlos Lourenco, L. Kluberg, N.S. Topilskaya, F. Vazeille, A. Musso, Serban Constantinescu, A.A. Grigorian, P. Liaud, E. Descroix, Sanda Dita, Mauro Gallio, A. Borhani, and V. Boldea
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Deuterium, Nucleon, Ion
Published: 1998
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19. New results on J/ψ from the NA50 experiment

Author: A. Piccotti, João Cruz, Roberta Arnaldi, J.-R. Pizzi, F. Prino, A. Bussiere, Ermanno Vercellin, Paolo Giubellino, H.R. Gulkanyan, Helena Santos, M. Mac Cormick, P. Petiau, A. Marzari-Chiesa, W.L. Prado da Silva, F. Sigaudo, F.F. Guber, Y.K. Gavrilov, N. Willis, S. Ramos, O. Drapier, P. Sonderegger, G. Puddu, Luciano Ramello, A. Devaux, M.B. Golubeva, Enrico Scalas, G. L. Usai, Alexey Kurepin, G. Dellacasa, Alberto Masoni, Sanda Dita, D. Jouan, P. Rato Mendes, S. Serci, C. Quintans, M. Atayan, N. De Marco, T. Claudino, B. Chaurand, X. Tarrago, A. Romana, C. Gerschel, Pietro Cortese, Calin Alexa, M. Bedjidian, C. Castanier, Brigitte Cheynis, S. Grigorian, Mauro Gallio, Carlos Lourenco, P. Bordalo, R. Hakobyan, V. Boldea, Enrico Scomparin, L. Kluberg, N.S. Topilskaya, A. De Falco, J.-Y. Grossiord, A. Guichard, Stefania Beole, T. Wu, M. Gonin, L. Capelli, A. Musso, P. Force, Mario Sitta, Marek Idzik, P. Saturnini, J. Fargeix, C. Baglin, P. Macciotta, Massimo Masera, E. Chiavassa, Ruben Shahoyan, M. P. Comets, B. Espagnon, R. Haroutunian, G. Borges, T.L. Karavitcheva, Corrado Cicalo, Marco Monteno, Y. Le Bornec, L. Riccati, J. Castor, S. Borenstein, L. Villatte, A. Baldit, Serban Constantinescu, Bruno Alessandro, and A.A. Grigorian
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Muon, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Nuclear Theory, Plasma, 01 natural sciences, Atomic and Molecular Physics, and Optics, Charged particle, Ion, Renormalization, Nuclear physics, 0103 physical sciences, Quark–gluon plasma, High Energy Physics::Experiment, Heavy ion, Nuclear Experiment, 010306 general physics
Abstract: The NA50 experiment studies the production of J/γ in Pb+Pb collisions. The anomalous J/ψ suppression in relativistic heavy ion collisions, considered an unambiguous signature for the formation of a quark gluon plasma, is studied in the dimuon channel, using as reference the Drell-Yan muon pairs. Preliminary results from the analysis of the 2000 data, with the target region vacuum, are presented and compared to an update of those obtained from previous data samples.
Published: 2003
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20. Charged particle multiplicity measurements in NA60

Author: Franck Manso, K. Banicz, J. Lozano, H. Vardanyan, A. De Falco, Z. Li, P. Pillot, S. Serci, A. Colla, Alessandro Ferretti, H. J. Specht, Corrado Cicalo, B. Chaurand, Michele Floris, G. Puddu, H. Gulkanian, Pietro Cortese, A. Guichard, P. Parracho, Chiara Oppedisano, P. Rosinsky, M. Keil, Carlos Lourenco, Roberta Arnaldi, Enrico Scomparin, A.A. Grigorian, K. Borer, P. Sonderegger, Jean-Yves Grossiord, Jan Buytaert, Brigitte Cheynis, E. Radermacher, S. Damjanovic, J. Castor, P. Force, A. David, P. Ramalhete, Ruben Shahoyan, Rob Veenhof, J. M. Heuser, E. Tveiten, J. Seixas, N. De Marco, Wen-Chang Chen, Hiroaki Ohnishi, A. Devaux, Raphael Noel Tieulent, Alberto Masoni, A. Neves, N. Guettet, H. En'yo, L. Kluberg, Hermine Katharina Wöhri, A. Drees, G. L. Usai, M. Floris, Laurent Ducroux, Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), NA60, Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: History, Particle physics, Silicon, Physics::Instrumentation and Detectors, Nuclear Theory, chemistry.chemical_element, 01 natural sciences, 7. Clean energy, Education, law.invention, Telescope, Nuclear physics, Muon spectrometer, law, 0103 physical sciences, Nuclear Experiment, 010303 astronomy & astrophysics, Physics, Large Hadron Collider, 010308 nuclear & particles physics, Detector, Multiplicity (mathematics), Charged particle, Computer Science Applications, Vertex (geometry), chemistry, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], High Energy Physics::Experiment
Abstract: NA60; The NA60 experiment at the CERN SPS studies dimuon production in nucleusnucleus and proton-nucleus collisions. One of the main detectors in the apparatus is the silicon pixel vertex telescope, which tracks charged particles in the target region. This detector complements the information from the muon spectrometer, improving the dimuon mass resolution and signal-to-noise ratio of the experiment, overcoming the main limitations of its predecessors. The silicon vertex telescope also provides the experiment with the capability of measuring charged particle multiplicities. In this paper we briefly describe the experiment and some preliminary results on charged particle multiplicities for two different colliding systems at different incident beam energies (Pb-Pb at 30 AGeV and In-In at 158 AGeV).
Published: 2005
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21. J/$\psi$ production and suppression at SPS energies

Author: Ermanno Vercellin, F. Sigaudo, Marco Monteno, G. Puddu, Y. Le Bornec, H.R. Gulkanyan, T. Wu, X. Tarrago, C. Castanier, Bruno Alessandro, G. L. Usai, G. Borges, J. Castor, T.L. Karavitcheva, Corrado Cicalo, Paolo Giubellino, F.F. Guber, A. Marzari-Chiesa, M. Mac Cormick, B. Chaurand, Roberta Arnaldi, N. Willis, A.A. Grigorian, A. Devaux, C. Gerschel, Alberto Masoni, Luciano Ramello, Brigitte Cheynis, M. P. Comets, A. Musso, Marek Idzik, Serban Constantinescu, Stefania Beole, P Cortese, S. Ramos, Mauro Gallio, P. Petiau, N. De Marco, S. Serci, V. Boldea, P. Force, J. Fargeix, Smbat Grigoryan, P. Sonderegger, Mario Sitta, L. Villatte, Calin Alexa, P. Bordalo, A. Piccotti, Massimo Masera, F. Prino, L. Riccati, M.B. Golubeva, Sanda Dita, D. Jouan, A. De Falco, E. Chiavassa, Ruben Shahoyan, P. Saturnini, Enrico Scomparin, G. Dellacasa, Helena Santos, A. Guichard, Alexey Kurepin, Carlos Lourenco, L. Kluberg, N.S. Topilskaya, J.-R. Pizzi, C. Quintans, M. Atayan, Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), NA50, Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Proton, 010308 nuclear & particles physics, Absorption cross section, Nuclear matter, 01 natural sciences, 7. Clean energy, Ion, Momentum, Nuclear physics, Cross section (physics), 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, 010306 general physics, Nucleon, Nuclear Experiment
Abstract: NA50; We present the set of measurements carried out by the NA50 experiment to study J$\psi$ production in proton- and ion-induced reactions. We also make use of results obtained previously under similar conditions by experiments NA51, NA38 and NA3. All these measurements were performed in fixed target experiments at the CERN SPS. Due to accelerator constraints, momentum was 450, 400 and 200 GeV/c for incident proton beams (corresponding to $\sqrt{s}$=29.0, 27.4, 19.4 GeV} respectively) whereas, for ion beams, incident momentum was 200 GeV/nucleon for oxygen and sulfur and 158 GeV/nucleon for Pb beams ($\sqrt{s}$=19.4 and $\sqrt{s}$=17.2 GeV} respectively). The p–A data allow us to determine with high accuracy the absorption cross section of the (pre-)resonant $c\bar{c}$ state with nuclear matter. The J$\psi$ production cross section normally expected for ion-induced reactions can then be determined and compared to the results obtained from the data collected for oxygen- and sulfur-induced collisions. Finally, we also present the most recent results on J$\psi$ production in Pb–Pb interactions. They are based on the last data sample collected with an improved experimental set-up and are compared with the expectations inferred from similar measurements on lighter nuclei collisions.
Published: 2004
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22. Transverse momentum dependence of charmonium suppression in Pb-Pb collisions at the CERN SPS

Author: A.B. Kurepin, B. Alessandro, C. Alexa, R. Arnaldi, M. Atayan, S. Beolè, V. Boldea, P. Bordalo, G. Borges, C. Castanier, J. Castor, B. Chaurand, B. Cheynis, E. Chiavassa, C. Cicalo, M.P. Comets, S. Constantinescu, P. Cortese, A. De Falco, N. De Marco, G. Dellacasa, A. Devaux, S. Dita, J. Fargeix, P. Force, M. Gallio, C. Gerschel, P. Giubellino, M.B. Golubeva, A.A. Grigorian, S. Grigorian, F.F. Guber, A. Guichard, H. Gulkanyan, M. Idzik, D. Jouan, T.L. Karavitcheva, L. Kluberg, Y. Le Bornec, C. Lourenço, M. Mac Cormick, A. Marzari-Chiesa, M. Masera, A. Masoni, M. Monteno, A. Musso, P. Petiau, A. Piccotti, J.R. Pizzi, F. Prino, G. Puddu, C. Quintans, L. Ramello, S. Ramos, L. Riccati, H. Santos, P. Saturnini, E. Scomparin, S. Serci, R. Shahoyan, F. Sigaudo, M. Sitta, P. Sonderegger, X. Tarrago, N.S. Topilskaya, G.L. Usai, E. Vercellin, L. Villatte, N. Willis, T. Wu, Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), NA50, Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
Subjects: Physics, Nuclear and High Energy Physics, Range (particle radiation), Large Hadron Collider, 010308 nuclear & particles physics, 01 natural sciences, Nuclear physics, Cross section (physics), Amplitude, 0103 physical sciences, Transverse momentum, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Atomic physics, 010306 general physics, Nucleon, Nuclear Experiment
Abstract: Charmonium suppression in Pb-Pb collisions at 158 GeV/c per nucleon is investigated in detail with the study of the transverse momentum distributions of J/ ψ as a function of the centrality of the collision. It is shown that the observed J/ ψ suppression in Pb-Pb interactions is particularly significant mainly at low transverse momentum where it strongly depends on centrality. For peripheral Pb-Pb collisions, the transverse momentum dependence of the J/ ψ cross section is, as a function of centrality, qualitatively similar to the dependence observed in p-A and S-U collisions. Comparing peripheral and central Pb-Pb collisions, the data show a relative suppression in the whole p T range although its amplitude significantly decreases with increasing p T and becomes almost p T independent for the highest p T values.
Published: 2004
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23. The NA60 silicon pixel telescope

Author: H. Vardanyan, Enrico Scomparin, E. Radermacher, R. Shahoyan, Z. Li, P. Rosinsky, J. Seixas, A. De Falco, Alberto Masoni, Raphael Noel Tieulent, Pcf Parracho, Pietro Cortese, Brigitte Cheynis, Laurent Ducroux, Corrado Cicalo, Roberta Arnaldi, Wen-Chang Chen, Carlos Lourenco, Jan Buytaert, S. Serci, L. Kluberg, B. Chaurand, N. De Marco, A. Devaux, J. M. Heuser, A.A. Grigorian, J. Lozano, A. David, J. Castor, Hermine Katharina Wöhri, A. Neves, Markus Keil, A. Colla, Hiroaki Ohnishi, Alessandro Ferretti, A. Guichard, Michele Floris, Chiara Oppedisano, N. Guettet, P. Force, G. Puddu, K. Borer, R. Veenhof, A. Drees, G. L. Usai, H. En'yo, Franck Manso, K. Banicz, Jy Grossiord, H. Gulkanian, P. Sonderegger, Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Stephen J. Watts, NA60, Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: Nuclear and High Energy Physics, Particle physics, Physics::Instrumentation and Detectors, Nuclear Theory, Radiation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, law.invention, Nuclear physics, Telescope, law, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Vector meson, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, Nuclear Experiment, Instrumentation, Physics, Large Hadron Collider, Pixel, 010308 nuclear & particles physics, Detector, Dipole, Thermal radiation, High Energy Physics::Experiment
Abstract: The NA60 experiment studies the production of open charm and prompt dimuons in proton–nucleus and nucleus–nucleus collisions at the CERN SPS. The main goal of NA60 is the study of various possible signatures of the transition from hadronic to deconfined partonic matter, e.g. anomalous charmonium suppression, dimuons from thermal radiation and modifications of vector meson properties. Reaching these goals is facilitated by the use of new state-of-the-art silicon detectors in the vertex region. Downstream of the target and inside a 2.5 T dipole magnetic field a pixel telescope measures the charged tracks originating from the collisions. The full pixel telescope consists of 16 planes with 96 ALICE1LHCb pixel detector assemblies in total. This paper describes the setup of the pixel telescope, results from tests as well as the expected implications of the operation of the silicon detectors in the harsh radiation environment of the NA60 experiment, with heavy-ion collisions.
Published: 2003
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24. RECENT RESULTS OF J/Ψ SUPPRESSION FROM THE NA50 EXPERIMENT AT CERN SPS

Author: Bruno Espagnon, Ermanno Vercellin, Brigitte Cheynis, F. Sigaudo, Enrico Scalas, A. Defalco, S. Beole, João Cruz, L. Riccati, T. Wu, L. Villatte, V. Boldea, X. Tarrago, G. Borges, Paolo Giubellino, A. Marzari-Chiesa, Alberto Masoni, C. Castanier, S. Ramos, T.L. Karavitcheva, E. Chiavassa, Roberta Arnaldi, L. Capelli, T. Claudino, M. Masera, N DeMarco, P. Petiau, A. Romana, A. Piccotti, P. Bordalo, B. Chaurand, S. Serci, R. Hakobyan, P. Sonderegger, Calin Alexa, C. Gerschel, M. Bedjidian, M. Mac Cormick, M.P. Comets, A. Devaux, Mario Sitta, Helena Santos, G. L. Usai, O. Drapier, S. R. Borenstein, A. Baldit, H.R. Gulkanyan, Marco Monteno, F. Prino, P. Macciotta, N. Willis, A. Guichard, Sanda Dita, D. Jouan, J. Fargeix, C. Cicalo, A. Musso, Smbat Grigoryan, J. Castor, Enrico Scomparin, G. Dellacasa, Y. Lebornec, J.-Y. Grossiord, P. Force, Marek Idzik, M. Gonin, M. Gallio, P. Saturnini, F.F. Guber, Luciano Ramello, A. Bussiere, R. Haroutunian, Y.K. Gavrilov, C. Baglin, Alexey Kurepin, M.B. Golubeva, P. Rato-Mendes, Ruben Shahoyan, G. Puddu, Serban Constantinescu, A.A. Grigorian, Bruno Alessandro, W. Pradodasilva, Pietro Cortese, Carlos Lourenco, L. Kluberg, N.S. Topilskaya, C. Quintans, M. Atayan, and J.-R. Pizzi
Subjects: Physics, Nuclear physics, Large Hadron Collider
Published: 2003
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25. RESULTS FROM THE NA50 EXPERIMENT ON J/ψ SUPPRESSION AND CHARGED PARTICLE PSEUDORAPIDITY DISTRIBUTIONS IN PB–PB COLLISIONS

Author: V. Boldea, P. Petiau, P. Sonderegger, Paolo Giubellino, L. Capelli, G. Puddu, S. Beole, A. Bussiere, Mario Sitta, Ermanno Vercellin, L. Riccati, P. Bordalo, W.L. Prado da Silva, F. Sigaudo, R. Hakobyan, Roberta Arnaldi, M. Mac Cormick, Enrico Scalas, A. Musso, A. Defalco, A. Devaux, M. Masera, Bruno Espagnon, Sanda Dita, D. Jouan, P. Macciotta, S. Serci, G. L. Usai, M.B. Golubeva, Serban Constantinescu, A. Piccotti, G. Borges, O. Drapier, S. R. Borenstein, P. Saturnini, A. Romana, Y. Le Bornec, T.L. Karavitcheva, Helena Santos, João Cruz, Calin Alexa, P. Rato Mendes, X. Tarrago, A. Marzari-Chiesa, Alberto Masoni, C. Castanier, J.-Y. Grossiord, Bruno Alessandro, P. Force, M. Bedjidian, F. Prino, L. Villatte, B. Chaurand, S. Ramos, C. Gerschel, H.R. Gulkanyan, M.P. Comets, Ruben Shahoyan, N. Willis, C. Baglin, A. Guichard, A. Baldit, C. Cicalo, S. Grigorian, Enrico Scomparin, Brigitte Cheynis, M. Gonin, M. Gallio, Marek Idzik, R. Haroutunian, F.F. Guber, T. Wu, Marco Monteno, Luciano Ramello, Y.K. Gavrilov, T. Claudino, Alexey Kurepin, A.A. Grigorian, J. Castor, G. Dellacasa, Pietro Cortese, J. Fargeix, E. Chiavassa, Carlos Lourenco, L. Kluberg, N.S. Topilskaya, J.-R. Pizzi, C. Quintans, M. Atayan, and N DeMarco
Subjects: Physics, Particle physics, Pseudorapidity, Charged particle
Published: 2003
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26. The NA60 experiment at CERN SPS - First results and prospects

Author: J. Castor, N. De Marco, A. Neves, Markus Keil, Corrado Cicalo, A. Devaux, Z. Li, A. De Falco, A. Guichard, H. Gulkanian, P. Rosinsky, Michele Floris, A. Colla, S. Serci, Jan Buytaert, Alessandro Ferretti, H. Wo¨hri, A. Drees, P. Sonderegger, Chiara Oppedisano, K. Borer, Rob Veenhof, G. L. Usai, Roberta Arnaldi, H. Ohnishi, K. Banicz, Laurent Ducroux, W. Chen, N. Guettet, A.A. Grigorian, Raphael Noel Tieulent, Jean-Yves Grossiord, Brigitte Cheynis, B. Chaurand, P. Parracho, H. En'yo, Alberto Masoni, Ruben Shahoyan, Franck Manso, Pietro Cortese, Carlos Lourenco, L. Kluberg, A. David, H. Vardanyan, G. Puddu, J. Lozano, J. M. Heuser, Enrico Scomparin, Joao Seixas, E. Radermacher, P. Force, Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Yu. Oganessian, R. Kalpakchieva, NA60, Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Nuclear reaction, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Muon, Spectrometer, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Nuclear Theory, Detector, 01 natural sciences, Particle detector, law.invention, Semiconductor detector, Nuclear physics, Telescope, law, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics
Abstract: The NA60 experiment is taking place at the CERN SPS, to study the production of open charm and of prompt dimuons in collisions induced by proton and heavy ion beams on nuclear targets. In this paper we will present an overview of the detector concept, followed by a description of the newly developed silicon vertex telescope and its performance. Then we present some first results, including a dimuon mass spectrum obtained using the silicon vertex telescope.
Published: 2003
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27. The NA60 experiment: results and perspectives

Author: Hiroaki Ohnishi, Markus Keil, Franck Manso, J. Seixas, J.-Y. Grossiord, P. Parracho, Laurent Ducroux, Alessandro Ferretti, K. Banicz, C. Oppedisano, A. Neves, G. Puddu, Enrico Scomparin, Hermine Katharina Wöhri, S. Serci, A. Colla, A. Drees, K. Borer, P. Sonderegger, Michele Floris, G. L. Usai, B. Chaurand, C. Cicalo, A. De Falco, Pietro Cortese, P. Rosinsky, N. Guettet, Roberta Arnaldi, Wen-Chang Chen, J. M. Heuser, Carlos Lourenco, J. Lozano, L. Kluberg, Alberto Masoni, P. Force, H. Vardanyan, A. Devaux, Jan Buytaert, A. Guichard, E. Radermacher, Brigitte Cheynis, Z. Li, H. Gulkanian, A.A. Grigorian, A. David, Ruben Shahoyan, N. De Marco, Raphael Noel Tieulent, J. Castor, Rob Veenhof, H. En'yo, Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), NA60, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL)
Subjects: Physics, Particle physics, Muon, Large Hadron Collider, Meson, Spectrometer, Interaction point, 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, Detector, Nuclear Theory, 01 natural sciences, 7. Clean energy, law.invention, Nuclear physics, Telescope, law, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Nucleon, Nuclear Experiment, Particle Physics - Experiment
Abstract: NA60; The NA60 experiment takes place at the SPS at CERN, to study the production of open charm and prompt dimuons in collisions induced by proton and heavy ion beams on nuclear targets. For this task, several novel detector systems were added to the dimuon spectrometer and zero-degree calorimeter, which were previously used in the NA50 experiment. The main upgrade is a new silicon pixel vertex spectrometer. It tracks the charged particles that are produced through the collisions in the target and allows us to match their trajectories and momenta with those of the muons that are measured behind the hadron absorber in the muon spectrometer. Besides improving considerably the dimuon mass resolution, the vertex telescope measures the offset of each muon track with respect to the interaction point. This allows us to select events where charm mesons were produced. We present in this article first results from dimuon data that were acquired in Summer 2002 with a 400 GeV proton beam. A silicon microstrip telescope was used at that time, since only a part of the pixel telescope was completed. The results include an improved dimuon mass resolution and an extended phase space coverage when compared with previous experiments. Data from Pb-Pb collisions at 20 and 30 GeV per nucleon were collected in October 2002 with three planes of pixel detectors. We show the very good accuracy with which we could reconstruct the interaction vertex. We conclude with a reminder of our physics programme and the ongoing completion of the pixel detector telescope for the Indium-Indium run at 158 GeV per nucleon, scheduled for September and October 2003.
Published: 2003
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28. Transverse momentum and transverse mass distributions of mesons produced in p-A and Pb-Pb interactions at the CERN SPS

Author: A.B. Kurepin, B. Alessandro, C. Alexa, R. Arnaldi, M. Atayan, C. Baglin, A. Baldit, M. Bedjidian, S. Beolè, V. Boldea, P. Bordalo, S.R. Borenstein, G. Borges, A. Bussière, L. Capelli, C. Castanier, J. Castor, B. Chaurand, B. Cheynis, E. Chiavassa, C. Cicalò, T. Claudino, M.P. Comets, S. Constantinescu, P. Cortese, J. Cruz, A. De Falco, N. De Marco, G. Dellacasa, A. Devaux, S. Dita, O. Drapier, B. Espagnon, J. Fargeix, P. Force, M. Gallio, Y.K. Gavrilov, C. Gerschel, P. Giubellino, M.B. Golubeva, M. Gonin, A.A. Grigorian, S. Grigorian, J.Y. Grossiord, F.F. Guber, A. Guichard, H. Gulkanyan, R. Hakobyan, R. Haroutunian, M. Idzik, D. Jouan, T.L. Karavitcheva, L. Kluberg, Y. Le Bornec, C. Lourenço, P. Macciotta, M. Mac Cormick, A. Marzari-Chiesa, M. Masera, A. Masoni, M. Monteno, A. Musso, P. Petiau, A. Piccotti, J.R. Pizzi, W.L. Prado da Silva, F. Prino, G. Puddu, C. Quintans, L. Ramello, S. Ramos, P. Rato Mendes, L. Riccati, A. Romana, H. Santos, P. Saturnini, E. Scalas, E. Scomparin, S. Serci, R. Shahoyan, F. Sigaudo, M. Sitta, P. Sonderegger, X. Tarrago, N.S. Topilskaya, G.L. Usai, E. Vercellin, L. Villatte, N. Willis, and T. Wu
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Meson, Nuclear Theory, Hadron, Elementary particle, Parton, Quarkonium, Momentum, Nuclear physics, Transverse mass, High Energy Physics::Experiment, Nuclear Experiment, Boson
Abstract: We present a study of the transverse momentum and transverse mass of J ψ mesons produced in nucleus-nucleus and p-nucleus reactions. They include the most recent data collected by the NA50 experiment in PbPb and p-A reactions at 158 GeV/c and 400 GeV/c incident momentum respectively. Together with S-U results previously published by experiment NA38, the mean squared transverse momentum of J ψ mesons exhibit a scaling behaviour which could result from initial state parton interaction. However, for the most central PbPb collisions a saturation effect is observed as a function of centrality.
Published: 2003

29. New results on J/ψ from the NA50 experiment

Author: C. Quintans, B. Alessandro, C. Alexa, R. Arnaldi, M. Atayan, C. Baglin, A. Baldit, M. Bedjidian, S. Beolè, V. Boldea, P. Bordalo, S.R. Borenstein, G. Borges, A. Bussière, L. Capelli, C. Castanier, J. Castor, B. Chaurand, B. Cheynis, E. Chiavassa, C. Cicalò, T. Claudino, M.P. Comets, S. Constantinescu, P. Cortese, J. Cruz, A. De Falco, N. De Marco, G. Dellacasa, A. Devaux, S. Dita, O. Drapier, B. Espagnon, J. Fargeix, P. Force, M. Gallio, Y.K. Gavrilov, C. Gerschel, P. Giubellino, M.B. Golubeva, M. Gonin, A.A. Grigorian, S. Grigorian, J.Y. Grossiord, F.F. Guber, A. Guichard, H. Gulkanyan, R. Hakobyan, R. Haroutunian, M. Idzikn, 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, M. Monteno, A. Musso, P. Petiau, A. Piccotti, J.R. Pizzi, W.L. Prado da Silva, F. Prino, G. Puddu, L. Ramello, S. Ramos, P. Rato Mendes, L. Riccati, A. Romana, H. Santos, P. Saturnini, E. Scalas, E. Scomparin, S. Serci, R. Shahoyan, F. Sigaudo, M. Sitta, P. Sonderegger, X. Tarrago, N.S. Topilskaya, G.L. Usai, E. Vercellin, L. Villatte, N. Willis, and T. Wu
Published: 2003
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30. Charmonia and Drell-Yan production in proton-nucleus collisions at the CERN SPS

Author: J.Y. Grossiord, Yu.K. Gavrilov, R. Arnaldi, E. Vercellin, R. Shahoyan, T. Claudino, Mario Sitta, C. Alexa, S. Constantinescu, S. Beolè, X. Tarrago, J. Fargeix, L Capelli, C. Lourenço, C. Baglin, A. Bussiere, N.S. Topilskaya, Laurent Ducroux, A. Marzari-Chiesa, Marco Monteno, P. Sonderegger, P. Rato Mendes, C. Quintans, M. Atayan, Paolo Giubellino, P. Macciotta, L. Kluberg, B. Chaurand, C. Gerschel, M. Mac Cormick, Pietro Cortese, L Villatte, J. Castor, N. Willis, Enrico Scomparin, G. Borges, S. Borenstein, C Castanier, T.L. Karavitcheva, João Cruz, S. Dita, S. Ramos, F Prino, L. Ramello, M. Gonin, G. Puddu, M. P. Comets, V. Boldea, E. Chiavassa, A. Piccotti, M.B. Golubeva, B. Espagnon, S. Grigorian, A.A. Grigorian, J.-R. Pizzi, W.L. Prado da Silva, F. Sigaudo, Y. Le Bornec, M. Gallio, A. Musso, P. Force, A. B. Kurepin, M. Masera, O. Drapier, P. Petiau, H. Gulkanyan, Enrico Scalas, Bruno Alessandro, F.F. Guber, N. De Marco, B. Cheynis, D. Jouan, G.L. Usai, N. Constans, P. Bordalo, R. Hakobyan, C. Cicalò, A. De Falco, L. Riccati, A. Devaux, P. Saturnini, S. Serci, Marek Idzik, G. Dellacasa, Helena Santos, A. Romana, A. Masoni, A. Guichard, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), NA50, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Hadron, Nuclear Theory, Elementary particle, Nuclear matter, Quarkonium, 01 natural sciences, Baryon, Nuclear physics, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Nucleon, Nuclear Experiment, Glauber, Particle Physics - Experiment
Abstract: Charmonium production in p-A collisions is a unique tool for the study of the interaction of bound ccbar in nuclear matter. It can provide details on the basic features of the resonance formation mechanism and, in particular, on its non-perturbative aspects. In this Letter, we present an experimental study of Charmonia and Drell-Yan production in proton-nucleus collisions at 450GeV/c. The results are analyzed in the framework of the Glauber model and lead to the values of the nuclear absorption cross-section sigma^abs_pA for j/psi and psi'. Then, we compare the J/psi absorption in proton-nucleus and sulphur-uranium interactions, using NA38 data. We obtain that, for the J/psi, omega^abs_pA and omega^abs_SU are compatible, showing that no sizeable additional suppression mechanism in present S-U collisions, and confirming that the anomalous J/psi suppression only sets in for Pb-Pb interactions.
Published: 2003
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31. $\phi$ production in Pb-Pb collisions at 158 GeV/c per nucleon incident momentum

Author: V. Caponi, G. L. Usai, C. Quintans, M. Atayan, Mario Sitta, Sergio Serci, P. Rato Mendes, C. Baglin, B. Chaurand, J.-Y. Grossiord, C. Gerschel, Roberta Arnaldi, A. Baldit, P. Macciotta, N. Willis, Serban Constantinescu, A. Marzari-Chiesa, Y.K. Gavrilov, A. Masoni, N. Constans, S. Grigoryan, A. Devaux, A. Bussiere, Paolo Giubellino, Alexey Kurepin, B. Espagnon, P. Bordalo, J.-R. Pizzi, H.R. Gulkanyan, F.F. Guber, R. Hakobyan, A.A. Grigorian, Mauro Gallio, V. Boldea, X. Tarrago, Massimo Masera, O. Drapier, Marco Monteno, Y. Le Bornec, C. Castanier, Laurent Ducroux, Luciano Ramello, J. Astruc, E. Chiavassa, Ruben Shahoyan, J. Fargeix, Marek Idzik, A. Piccotti, L. Capelli, João Cruz, A. Guichard, M.B. Golubeva, J. Castor, G. Borges, Ermanno Vercellin, Corrado Cicalo, A. De Falco, T.L. Karavitcheva, N. De Marco, Sanda Dita, D. Jouan, T. Claudino, P. Saturnini, W.L. Prado da Silva, F. Sigaudo, Pietro Cortese, Enrico Scalas, L. Villatte, F Prino, Carlos Lourenco, L. Riccati, Enrico Scomparin, S. Silva, L. Kluberg, N.S. Topilskaya, M. Gonin, Brigitte Cheynis, I. Chevrot, A. Romana, Calin Alexa, S. Ramos, M. P. Comets, G. Dellacasa, Helena Santos, P. Petiau, P. Sonderegger, Bruno Alessandro, M. Mac Cormick, G. Puddu, Stefania Beole, P. Force, A. Musso, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), NA50, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Muon, Meson, 010308 nuclear & particles physics, Nuclear Theory, Hadron, 16. Peace & justice, 01 natural sciences, Nuclear physics, Particle decay, Pair production, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Transverse mass, High Energy Physics::Experiment, Rapidity, Nuclear Experiment, 010306 general physics, Nucleon
Abstract: The production of vector mesons φ , ρ and ω has been measured in Pb–Pb collisions at 158 GeV/ c per nucleon incident momentum at the CERN/SPS. The muon spectrometer of experiment NA50 detects φ , ρ and ω mesons via their μ + μ − decay channel in the collision center of mass rapidity range 0⩽ y CM ⩽1. The results reported here show that the relative production of the φ compared to the ( ρ + ω ) and the φ multiplicity per participant nucleon ( N part ) increase with the centrality of the collision. On the other hand, the ( ρ + ω ) multiplicity per participant does not exhibit any N part dependence within our errors. The inverse slope parameter as deduced from an exponential fit to the φ transverse mass distribution is 228±10 MeV. Our results are compared with those obtained by experiment NA49 and with theoretical calculations.
Published: 2003
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32. Charmonia absorption in p-A collisions at the CERN SPS results and implications for PbPb interactions

Author: P. Cortese, B. Alessandro, C. Alexa, R. Arnaldi, M. Atayan, C. Baglin, A. Baldit, M. Bedjidian, S. Beolè, P. Bordalo, S.R. Borenstein, G. Borges, A. Bussière, L. Capelli, C. Castanier, J. Castor, B. Chaurand, B. Cheynis, E. Chiavassa, C. Cicaló, T. Claudino, S. Constantinescu, J. Cruz, A. de Falco, N. de Marco, G. Dellacasa, A. Devaux, S. Dita, O. Drapier, B. Espagnon, J. Fargiex, P. Force, M. Gallio, Y.K. Gavrilov, C. Gerschel, P. Giubellino, M.B. Golubeva, M. Gonin, A.A. Grigorian, S. 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, M. Monteno, A. Musso, P. Petiau, A. Piccotti, J.R. Pizzi, W.L. Prado da Silva, F. Prino, G. Puddu, C. Quintans, L. Ramello, S. Ramos, P. Rato Mendex, L. Riccati, A. Romana, H. Santos, P. Saturnini, E. Scalas, E. Scomparin, S. Serci, R. Shahoyan, M. Sitta, P. Sonderegger, X. Tarrago, N.S. Topilskaya, G.L. Usai, E. Vercellin, L. Villatte, N. Willis, and T. Wu
Subjects: Physics, Nuclear and High Energy Physics, Claude bernard, Humanities
Abstract: P. Cortese’) for the NA50 Collaboration: B. Alessandrol’) C. Alexa4) R. Arnaldi M. Bedjidian”),‘S. Beole hglin’), A. Baldit3), ‘ll) ‘V. Boldea4), P. Bordalo’y@, S.R. Boreusteinlo~b), G. Borges7), A. Bussiere’), L. Capelli “),‘C. Castanier3), J. Castor 3), B. Chaurandl”), B. Cheynis12), E. Chiavassa”), C. Cicalb5), T. Claudino ‘) M.P. Cometsg), S. Constantinescu , 4), P. Cortesel), J. Cruz’), A. de Falco’), N. de Marco”), G. Dellacasa’), A. Devaux3), S. Dita4), 0. Drapier”), B. Espagnon3), J. Fargeix3), P. Force3), M. Gallio 11), Y.K. Gavrilov’), C. Gerschelg), P. Giubellinoll>c), M.B. Golubeva’), M. Gonin”), A.A. Grigorian13) S. Grigorian13), J Y Grossiord12) F.F. Guber’) A. Guichard . . 12), H. Gulkanyan 13), R. Haroutunian”), M. Idzikl’~d~, D. Jouan’), T.L. Karavitchew?) R. Hakobyan’3), L. Kluberg’O) A.B. Kurepin8), Y. Le Bornecg), C. Lourenqo’) P. Macciotta5), M. Mac Cormick;) A. Marzari-Chiesa”), M. Masera”), A. Masoni5), M. Mouteno”), A. Musso~~), P. Petiau”), A. Piccotti”), J.R. Pizzi”), W.L. Prado da Silvall*e), F. Prino”), G. Puddu’), C. Quintans’), L. Ramello’), S. Ftarno~~~~), P. Rata Mendes ‘), L. Riccati”), A. Romana’O), H. Santos’), P. Saturnini3), E. Scala& E. Scomparin 11), S. Serci5), R. Shahoyan7f), F. Sigaudo”), M. Sitta’), P. Sonderegger’+), X. Tarragog), N.S. Topilskaya8), G.L. Usai5), E. Vercellin”), L. Villatteg), N. Willisg), T. Wug). i) Univ. de1 Piemonte Orientale, Alessaudria and INFN-Torino, Italy. 2, LAPP, CNRSIN2P3, Annecy-le-Vieux, France. 3, LPC, Univ. Blaise Pascal and CNRSIN2P3, Aubiere, France. 4, IFA, Bucharest, Romania. 5, Univ. di Cagliari and INFN, Cagliari, Italy. 6, CERN, Geneva, Switzerland. ?) LIP, Lisbon, Portugal. 8, INR, Moscow, Russia. ‘1 IPN, Univ. de Paris-Sud and CNRS-IN2P3, Orsay, France. lo) Laboratoire Leprince-Ringuet, Ecole Polytechnique and CNRS-INZPS, Palaiseau, France. ii) Univ. di Torino and INFN, Torino, Italy. 12) IPN, Univ. Claude Bernard Lyon-I and CNRSIN2P3, Villeurbaune, France. i3) YerPhI, Yerevan, Armenia. a) Also at IST, Lisbon, Portugal. b, On leave from York College, CUNY, New York, USA. =) Also at CERN, Geneva, Switzerland. d, Also at FPNT, Cracow, Poland. e, Now at UERJ, Rio de Janeiro, Brazil. ‘) On leave from YerPhI, Yerevan, Armenia.
Published: 2003

33. Transverse momentum distribution of J/Ψ produced in PbPb and p-A interactions at the CERN SPS

Author: N.S. Topilskaya, B. Alessandro, C. Alexa, R. Arnaldi, M. Atayan, C. Baglin, A. Baldit, M. Bedjidian, S. Beolè, V. Boldea, P. Bordalo, G. Borges, A. Bussière, L. Capelli, C. Castanier, J. Castor, B. Chaurand, I. Chevrot, B. Cheynis, E. Chiavassa, C. Cicalo, T. Claudino, M.P. Comets, N. Constans, S. Constantinescu, P. Cortese, A.De Falco, G. Dellacasa, N.De Marco, 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, S. Grigorian, J.I. 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, M. Monteno, A. Musso, P. Petiau, A. Piccotti, J.R. Pizzi, W.L. Prado da Silva, F. Prino, G. Puddu, C. Quintans, L. Ramello, S. Ramos, P. Rato-Mendes, L. Riccati, A. Romana, H. Santos, P. Saturnini, E. Scalas, E. Scomparin, S. Serci, R. Shahoyan, F. Sigaudo, M. Sitta, C. Soave, P. Sonderegger, X. Tarrago, G.L. Usai, E. Vercellin, L. Villatte, and N. Willis
Subjects: Nuclear reaction, Physics, Nuclear and High Energy Physics, Particle physics, Muon, Meson, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Elementary particle, Quarkonium, Nuclear physics, Transverse mass, High Energy Physics::Experiment, Nuclear Experiment, Nucleon
Abstract: Muon pairs produced in Pb Pb interactions at 158 GeV/c per nucleon and in p-A interactions at 400 GeV/c, together with older S-U results obtained at 200 GeV/c are used to study the transverse momentum and transverse mass distributions of the J/Ψ.
Published: 2003

34. EVIDENCE FOR DECONFINEMENT FROM THE J/ψ SUPPRESSION PATTERN IN Pb-Pb COLLISIONS BY THE NA50 EXPERIMENT

Author: M. Gonin, M.P. Comets, Bruno Alessandro, Bruno Espagnon, F.F. Guber, Paolo Giubellino, S. Silva, Luciano Ramello, Brigitte Cheynis, L. Casagrande, Y.K. Gavrilov, G. Puddu, M. Masera, T. Chambon, Alexey Kurepin, N. De Marco, I. Ropotar, S. Serci, Serban Constantinescu, A. Musso, N. Constans, G. Dellacasa, L. Villatte, H.R. Gulkanyan, P. Petiau, J.-R. Pizzi, P. Saturnini, X. Tarrago, E. Chiavassa, I. Chevrot, C. Soave, A.A. Grigorian, P. Sonderegger, M.C. Abreu, Sanda Dita, D. Jouan, Marco Monteno, M. Bedjidian, A. Piccotti, A. Bussiere, F. Prino, Marek Idzik, Laurent Ducroux, G. L. Usai, T.L. Karavitcheva, V. Boldea, M.B. Golubeva, J. Castor, S. Mehrabyan, Ermanno Vercellin, A. Baldit, N. Willis, L. Capelli, P. Rato Mendes, Carlos Lourenco, B. Chaurand, J. Fargeix, L. Kluberg, N.S. Topilskaya, C. Gerschel, A. Romana, Y. Le Bornec, P. Bordalo, R. Hakobyan, Calin Alexa, A. Devaux, C. Quintans, M. Atayan, T. Claudino, Enrico Scomparin, L. Riccati, A. Marzari-Chiesa, S. Ramos, Alberto Masoni, Mario Sitta, Roberta Arnaldi, O. Drapier, J.-Y. Grossiord, A. De Falco, C. Cicalo, P. Force, M. Mac Cormick, P. Macciotta, S. Beole, M. Gallio, A. Guichard, R. Haroutunian, Ruben Shahoyan, and C. Baglin
Subjects: Physics, Particle physics, Deconfinement
Published: 2002
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35. Latest results from NA50 on J/ψ suppression in Pb-Pb collisions at 158 GeV/c

Author: L. Capelli, O. Drapier, S. R. Borenstein, H.R. Gulkanyan, T. Claudino, Alberto Masoni, E. Chiavassa, A. Baldit, X. Tarrago, A. Marzari-Chiesa, J.-Y. Grossiord, N. Constans, Paolo Giubellino, C. Castanier, S. Ramos, Enrico Scomparin, Ermanno Vercellin, A. Guichard, Marek Idzik, G. Dellacasa, A.A. Grigorian, W.L. Prado da Silva, F. Sigaudo, M. Bedjidian, P. Rato Mendes, Y.K. Gavrilov, Sanda Dita, D. Jouan, N. De Marco, F. Prino, L. Villatte, G. L. Usai, Enrico Scalas, Alexey Kurepin, A. Romana, Y. Le Bornec, P. Bordalo, C. Quintans, A. De Falco, Calin Alexa, Mario Sitta, M. Atayan, R. Hakobyan, Bruno Espagnon, N. Willis, L. Riccati, C. Cicalo, Bruno Alessandro, A. Devaux, G. Puddu, B. Chaurand, Roberta Arnaldi, A. Musso, A. Piccotti, M. Gonin, J. Fargeix, F.F. Guber, Pietro Cortese, João Cruz, Luciano Ramello, C. Gerschel, Serban Constantinescu, M. Mac Cormick, A. Bussiere, Helena Santos, G. Borges, M.C. Abreu, M. Masera, M.B. Golubeva, Carlos Lourenco, P. Macciotta, T.L. Karavitcheva, S. Serci, L. Kluberg, N.S. Topilskaya, P. Petiau, J.-R. Pizzi, Marco Monteno, P. Saturnini, P. Sonderegger, S. Silva, M.P. Comets, J. Castor, S. Grigorian, Brigitte Cheynis, P. Force, S. Beole, Ruben Shahoyan, M. Gallio, R. Haroutunian, C. Baglin, and V. Boldea
Subjects: Nuclear physics, Nuclear reaction, Physics, Particle physics, Meson, Hadron, Quark model, Elementary particle, Nuclear Experiment, Kinetic energy, Nucleon, Quarkonium
Abstract: The main goal of the NA50 experiment is to study the J/ψ suppression pattern in Pb-Pb interactions, at 158 GeV/c per nucleon at the CERN SPS. We present here the results from the 1996 and 1998 data taking periods. We used new event selection procedures, different analysis techniques and different event centrality estimators and we can now confirm and extend our previous observation that the J/ψ is anomalously suppressed when going from peripheral to central Pb-Pb collisions. We observe that in peripheral collisions the J/ψ cross section per nucleon-nucleon collision agrees with the pattern inferred from a wide range of measurements with lighter systems, from p-p to S-U. When the collisions become more central a clear departure from this behavior is observed. The 1996 data show a sudden drop in the J/ψ production yield for transverse energy values above 40 GeV. The 1998 data provide a big improvement in the study of the most central region, where a second change in the pattern becomes visible. This suppres...
Published: 2002
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36. Scaling of charged particle multiplicity in Pb–Pb collisions at SPS energies

Author: Pietro Cortese, J.Y. Grossiord, Yu.K. Gavrilov, E. Vercellin, R. Arnaldi, M. Mac Cormick, Y. Le Bornec, A. Musso, P. Rato Mendes, A. Marzari-Chiesa, Marco Monteno, Bruno Alessandro, A. Romana, M. Masera, A. Masoni, B. Chaurand, P. Sonderegger, J. Castor, G.L. Usai, C. Gerschel, M.C. Abreu, Paolo Giubellino, G. Borges, T.L. Karavitcheva, L. Riccati, L. Villatte, I. Chevrot, S. Constantinescu, R. Haroutunian, V. Boldea, C. Quintans, M. Atayan, A. Baldit, X. Tarrago, C. Castanier, A. B. Kurepin, S. Serci, Mario Sitta, B. Espagnon, M. Gallio, P. Petiau, W.L. Prado da Silva, J.-R. Pizzi, A. Devaux, F. Sigaudo, S. Ramos, M. Bedjidian, L. Capelli, P. Force, C. Alexa, H. Gulkanyan, B. Cheynis, Enrico Scomparin, R. Shahoyan, N.S. Topilskaya, S. Grigorian, T. Claudino, Enrico Scalas, O. Drapier, C. Cicalò, S. Beolè, Laurent Ducroux, F.F. Guber, G. Puddu, G. Dellacasa, Helena Santos, L. Kluberg, A. De Falco, P. Saturnini, N. Willis, S. Dita, A. Piccotti, A.A. Grigorian, F. Prino, P. Bordalo, R. Hakobyan, M. P. Comets, Marek Idzik, L. Ramello, M. Gonin, M.B. Golubeva, J. Fargeix, A. Bussiere, A. Guichard, C. Lourenço, N. De Marco, D. Jouan, N. Constans, S. Silva, E. Chiavassa, C. Baglin, P. Macciotta, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), NA50, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, 010308 nuclear & particles physics, Nuclear Theory, Binary number, 7. Clean energy, 01 natural sciences, Power law, Charged particle, Nuclear physics, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, High Energy Physics::Experiment, Impact parameter, Multiplicity (chemistry), 010306 general physics, Nucleon, Nuclear Experiment, Scaling, Particle Physics - Experiment
Abstract: The charged particle multiplicity distribution dN ch / dη has been measured by the NA50 experiment in Pb–Pb collisions at the CERN SPS. Measurements were done at incident energies of 40 and 158 GeV per nucleon over a broad impact parameter range. The multiplicity distributions are studied as a function of centrality using the number of participating nucleons ( N part ), or the number of binary nucleon–nucleon collisions ( N coll ). Their values at midrapidity exhibit a power law scaling behaviour given by N part 1.00 and N coll 0.75 at 158 GeV. Compatible results are found for the scaling behaviour at 40 GeV. The width of the dN ch / dη distributions is larger at 158 than at 40 GeV/nucleon and decreases slightly with centrality at both energies. Our results are compared to similar studies performed by other experiments both at the CERN SPS and at RHIC.
Published: 2002
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37. Pseudorapidity distributions of charged particles as a function of centrality in Pb–Pb collisions at 158 and 40 GeV per nucleon incident energy

Author: M. Bedjidian, S. Grigorian, Paolo Giubellino, P. Rato Mendes, H.R. Gulkanyan, A. Masoni, B. Espagnon, B. Chaurand, C. Gerschel, A. Bussiere, O. Drapier, M. Mac Cormick, A. De Falco, C. Quintans, M. Atayan, J.-R. Pizzi, Stefania Beole, P. Saturnini, M. P. Comets, G. Dellacasa, P. Force, Bruno Alessandro, G. Puddu, Laurent Ducroux, X. Tarrago, J.-Y. Grossiord, S. Silva, C. Castanier, Mario Sitta, Helena Santos, F.F. Guber, T. Claudino, M.B. Golubeva, P. Petiau, A. Musso, Ermanno Vercellin, Sergio Serci, Brigitte Cheynis, Pietro Cortese, A. Piccotti, W.L. Prado da Silva, F. Sigaudo, Luciano Ramello, Roberta Arnaldi, P. Sonderegger, F. Prino, P. Bordalo, R. Hakobyan, Massimo Masera, Carlos Lourenco, Enrico Scalas, L. Riccati, Enrico Scomparin, N. Willis, A. Marzari-Chiesa, Marco Monteno, Y. Le Bornec, J. Castor, L. Villatte, Corrado Cicalo, L. Kluberg, N.S. Topilskaya, A. Devaux, M. Gonin, I. Chevrot, A. Guichard, A.A. Grigorian, Y.K. Gavrilov, E. Chiavassa, Ruben Shahoyan, A. Romana, Alexey Kurepin, C. Baglin, Calin Alexa, S. Ramos, Sanda Dita, D. Jouan, A. Baldit, J. Fargeix, Serban Constantinescu, Marek Idzik, G. Borges, M.C. Abreu, Mauro Gallio, T.L. Karavitcheva, V. Boldea, N. De Marco, R. Haroutunian, N. Constans, L. Capelli, G. L. Usai, P. Macciotta, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), NA50, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Nuclear and High Energy Physics, Range (particle radiation), Particle physics, Large Hadron Collider, 010308 nuclear & particles physics, Nuclear Theory, Function (mathematics), 01 natural sciences, 7. Clean energy, Charged particle, Nuclear physics, Transverse plane, Pseudorapidity, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, High Energy Physics::Experiment, Impact parameter, 010306 general physics, Nucleon, Nuclear Experiment, Particle Physics - Experiment
Abstract: The charged particle distributions dN ch / dη have been measured by the NA50 experiment in Pb–Pb collisions at the CERN SPS. Measurements have been done at incident energies of 158 and 40 GeV per nucleon over a broad impact parameter range. Results obtained with two independent centrality estimators, namely the neutral transverse energy E T and the forward energy E ZDC , are reported.
Published: 2002
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38. CHARMONIUM SUPPRESSION IN PB-PB COLLISIONS AND QUARK-GLUON DECONFINEMENT

Author: N. Constans, N. Willis, Laurent Ducroux, Bruno Alessandro, A. Bussiere, M.C. Abreu, G. Puddu, A.A. Grigorian, Y.K. Gavrilov, T. Chambon, Serban Constantinescu, P. Rato Mendes, M.P. Comets, M. Gonin, Ermanno Vercellin, T.L. Karavitcheva, J.-R. Pizzi, F.F. Guber, B. Chaurand, L. Casagrande, Alexey Kurepin, C. Gerschel, M.B. Golubeva, Marco Monteno, P. Petiau, N. De Marco, I. Chevrot, G. Dellacasa, Luciano Ramello, X. Tarrago, Y. Le Bornec, Paolo Giubellino, A. De Falco, E. Chiavassa, P. Sonderegger, A. Marzari-Chiesa, Mario Sitta, P. Saturnini, M. Masera, J. Castor, Marek Idzik, C. Quintans, S. Serci, A. Musso, M. Atayan, Enrico Scomparin, S. Ramos, S. Beole, L. Villatte, M. Gallio, A. Baldit, Bruno Espagnon, Carlos Lourenco, I. Ropotar, L. Kluberg, N.S. Topilskaya, A. Guichard, P. Bordalo, R. Haroutunian, Alberto Masoni, C. Baglin, R. Hakobyan, P. Force, A. Romana, A. Devaux, Calin Alexa, M. Mac Cormick, P. Macciotta, C. Cicalo, H.R. Gulkanyan, C. Soave, Ruben Shahoyan, J.-Y. Grossiord, O. Drapier, L. Riccati, S. Mehrabyan, Roberta Arnaldi, T. Claudino, A. Piccotti, Sanda Dita, D. Jouan, V. Boldea, L. Capelli, J. Fargeix, G. L. Usai, S. Silva, Brigitte Cheynis, M. Bedjidian, and F. Prino
Subjects: Quark, Physics, Particle physics, Deconfinement, Gluon
Published: 2001
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39. Centrality behaviour of J/$\psi$ production in NA50

Author: Ermanno Vercellin, W.L. Prado da Silva, F. Sigaudo, N. Constans, Enrico Scalas, G. Dellacasa, A. Guichard, Enrico Scomparin, Paolo Giubellino, Y.K. Gavrilov, S. Silva, M.P. Comets, Sanda Dita, D. Jouan, M. Mac Cormick, Alexey Kurepin, A. Romana, Y. Le Bornec, X. Tarrago, C. Castanier, P. Macciotta, Brigitte Cheynis, M. Masera, Calin Alexa, S. Serci, P. Rato Mendes, V. Boldea, P. Petiau, Roberta Arnaldi, Alberto Masoni, Ruben Shahoyan, H.R. Gulkanyan, A. Bussiere, J. Fargeix, B. Chaurand, Bruno Espagnon, S. Grigorian, C. Gerschel, L. Capelli, M.B. Golubeva, M. Gallio, P. Force, G. L. Usai, P. Sonderegger, A. Baldit, R. Haroutunian, Mario Sitta, J.-Y. Grossiord, C. Baglin, João Cruz, M. Gonin, G. Puddu, F.F. Guber, Marek Idzik, N. De Marco, Luciano Ramello, S. Beole, A. Musso, N. Willis, A. De Falco, C. Cicalo, G. Borges, M.C. Abreu, Serban Constantinescu, T.L. Karavitcheva, Sérgio Ramos, P. Bordalo, R. Hakobyan, A. Devaux, Bruno Alessandro, M. Bedjidian, F. Prino, L. Riccati, A. Piccotti, Helena Santos, A. Marzari-Chiesa, S. Ramos, A.A. Grigorian, P. Saturnini, E. Chiavassa, Pietro Cortese, O. Drapier, S. R. Borenstein, Carlos Lourenco, L. Kluberg, N.S. Topilskaya, C. Quintans, M. Atayan, J.-R. Pizzi, L. Villatte, Marco Monteno, J. Castor, T. Claudino, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), NA50, Laboratoire d'Annecy de Physique des Particules (LAPP), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: 020206 networking & telecommunications, 02 engineering and technology, 7. Clean energy, High Energy Physics - Phenomenology, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0202 electrical engineering, electronic engineering, information engineering, Production (economics), 020201 artificial intelligence & image processing, High Energy Physics::Experiment, Centrality, Nuclear Experiment, Mathematical economics, Particle Physics - Experiment, Mathematics
Abstract: The J/$\psi$ production in 158 A GeV Pb-Pb interactions is studied, in the dimuon decay channel, as a function of centrality, as measured with the electromagnetic or with the very forward calorimeters. After a first sharp variation at mid centrality, both patterns continue to fall down and exhibit a curvature change at high centrality values. This trend excludes any conventional hadronic model and is in agreement with a deconfined quark-gluon phase scenario. We report also preliminary results on the measured charged multiplicity, as given by a dedicated detector., Comment: 5 pages, 7 figures (in eps) talk given at XXXI International Symposium on Multiparticle Dynamics, Sep. 1-7, 2001, Datong China URL http://ismd31.ccnu.edu.cn/
Published: 2001

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

Author: 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, 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
Subjects: Nuclear reaction, Physics, Nuclear and High Energy Physics, Particle physics, Meson, Nuclear Theory, Hadron, Elementary particle, Quarkonium, Atomic and Molecular Physics, and Optics, Nuclear physics, Strange matter, Impact parameter, Nuclear Experiment, Nucleon
Abstract: The NA50 experiment has measured, at the CERN SPS, the dimuon production in PbPb 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 PbPb collisions at the SPS.
Published: 2001

41. The dependence of the anomalous $J/\psi$ suppression on the number of participant nucleons

Author: S. Beolè, P. Rato Mendes, G. Puddu, F.F. Guber, J.Y. Grossiord, B. Chaurand, Yu.K. Gavrilov, A. Bussiere, Enrico Scomparin, A. De Falco, R. Arnaldi, Paolo Giubellino, C. Gerschel, A. B. Kurepin, B. Espagnon, G.L. Usai, F. Sigaudo, L. Riccati, A. Guichard, V. Boldea, C. Quintans, M. Atayan, Mario Sitta, N. Willis, N.S. Topilskaya, P. Saturnini, N. De Marco, B. Cheynis, D. Jouan, S. Constantinescu, S. Dita, X. Tarrago, Bruno Alessandro, C. Castanier, E Scalas, H Santos, L. Capelli, I. Chevrot, N. Constans, L. Ramello, C. Alexa, M. Gonin, M. P. Comets, S. Silva, J.-R. Pizzi, J. Fargeix, C. Cicalò, A. Piccotti, M.B. Golubeva, M. Bedjidian, C. Baglin, P. Sonderegger, G. Borges, Laurent Ducroux, P. Force, S. Grigorian, A. Baldit, P. Petiau, O. Drapier, S. Ramos, T.L. Karavitcheva, H. Gulkanyan, M. Gallio, A.A. Grigorian, F. Prino, Y. Le Bornec, A. Musso, P. Macciotta, R. Haroutunian, C. Lourenço, Pietro Cortese, E. Chiavassa, A. Devaux, M. Mac Cormick, S. Serci, G. Dellacasa, M. Masera, A. Romana, A. Masoni, M.C. Abreu, R. Shahoyan, T. Claudino, A. Marzari-Chiesa, Marco Monteno, P. Bordalo, R. Hakobyan, J. Castor, E. Vercellin, L. Villatte, L. Kluberg, Marek Idzik, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), NA50, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: Deconfinement, Nuclear and High Energy Physics, Particle physics, Transverse energy, Hadron, Nuclear Theory, 158 Gev/C, Nucleus-nucleus collisions, 01 natural sciences, Nuclear physics, Cern-sps, 0103 physical sciences, 010306 general physics, Nuclear Experiment, Physics, Calorimeter (particle physics), Pattern, 010308 nuclear & particles physics, Zero (complex analysis), Function (mathematics), Pb-pb interactions, J-psi-suppression, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Quark–gluon plasma, High Energy Physics::Experiment, Nucleon, Glauber, Particle Physics - Experiment
Abstract: 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. info:eu-repo/semantics/publishedVersion
Published: 2001
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42. Transverse flow in heavy ion interactions at the CERN SPS

Author: P. Saturnini, 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, C. Castanier, 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, 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
Subjects: Physics, Nuclear reaction, Nuclear and High Energy Physics, Large Hadron Collider, Elliptic flow, Atomic and Molecular Physics, and Optics, Nuclear physics, Strange matter, Transverse plane, Thermalisation, State of matter, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment, Beam (structure)
Abstract: In the search for the quark-gluon plasma at CERN SPS, several signals were observed suggesting that this new state of matter was actually produced in the interactions induced by the lead beam at 158A GeV. The transverse flow phenomena characterize the distribution of the particles in the final state of the collision, and are expected to provide some indications about the initial state. More precisly, the existence of an elliptic flow directed along the reaction plane in the case of the non central collisions of two spherical nuclei, has been proposed to probe the thermalisation of the initial state. Indeed, the NA50 collaboration has measured these kind of effects in Pb-Pb collisions at 158A GeV, and we can conclude that the thermalisation of the initial state is actually present in these interactions. Conversely, there is no evidence for such a thermalisation in the NA38 data which were obtained with the sulphur beam at 200A GeV, neither in S-S nor in S-Cu interactions.
Published: 2001

43. Transverse momentum distributions of J/$\psi$, $\psi^{\prime}$, Drell-Yan and continuum dimuons produced in Pb-Pb interactions at the SPS

Author: G.L. Usai, L. Riccati, M. Gallio, J.Y. Grossiord, Yu.K. Gavrilov, L. Kluberg, R. Arnaldi, F Ohlson-Malek, F. Bellaiche, B. Cheynis, C. Cicalò, Mario Sitta, L. Villatte, C. Quintans, M. Atayan, S. Constantinescu, X. Tarrago, João Cruz, V. Boldea, M. P. Comets, I. Chevrot, G. Dellacasa, M. Mac Cormick, J. Fargeix, E. Chiavassa, C. Baglin, C. Alexa, A. Romana, A. Masoni, G. Puddu, Marek Idzik, P. Rato-Mendes, S. Beolè, Laurent Ducroux, A. Marzari-Chiesa, R. Shahoyan, P. Macciotta, S. Ramos, A. Baldit, Marco Monteno, L. Capelli, P. Bordalo, R. Hakobyan, A. De Falco, M.C. Abreu, A. Guichard, A. Devaux, S. Mourgues, B. Chaurand, I. Ropotar, C. Gerschel, P. Saturnini, P. Petiau, P. Force, J. Castor, P. Sonderegger, H. Gulkanyan, T.L. Karavitcheva, O. Drapier, A. Piccotti, E. Vercellin, A.A. Grigorian, F. Prino, R. Haroutunian, N. Willis, A. Bussiere, S. Dita, S Mehrabyan, F.F. Guber, B. Espagnon, Enrico Scomparin, C. Soave, A. B. Kurepin, L. Ramello, M. Gonin, M.B. Golubeva, C. Lourenço, Bruno Alessandro, M. Masera, T. Chambon, S. Serci, J.-R. Pizzi, N.S. Topilskaya, S. Silva, V. Capony, M. Bedjidian, Y. Le Bornec, A. Musso, L. Casagrande, N. De Marco, D. Jouan, N. Constans, Paolo Giubellino, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), NA50, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL)
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Muon, Continuum (measurement), 010308 nuclear & particles physics, Nuclear Theory, Drell–Yan process, 01 natural sciences, Nuclear physics, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Transverse momentum, High Energy Physics::Experiment, 010306 general physics, Nucleon, Nuclear Experiment, Particle Physics - Experiment
Abstract: Muon pairs produced in Pb-Pb interactions at 158~GeV/$c$ per nucleon are used to study the transverse momentum distributions of the J/$\psi$, $\psi^{\prime}$ and dimuons in the mass continuum. In particular, the dependence of these distributions on the centrality of the Pb-Pb collision is investigated in detail.
Published: 2000
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44. Evidence for deconfinement of quarks and gluons from the $J/psi$ suppression pattern measured in Pb-Pb collisions at the CERN-SPS

Author: A. Romana, A. Masoni, L. Villatte, G. Puddu, P. Bordalo, R. Hakobyan, Laurent Ducroux, C. Soave, A. Devaux, P. Force, M.C. Abreu, S. Constantinescu, X. Tarrago, L. Casagrande, B. Chaurand, A. Guichard, O. Drapier, C. Alexa, I. Chevrot, C. Gerschel, V. Boldea, A. Piccotti, M. Bedjidian, P. Petiau, H. Gulkanyan, M. P. Comets, A.A. Grigorian, J.-R. Pizzi, C. Lourenço, A. B. Kurepin, Marek Idzik, Paolo Giubellino, S. Beolè, G. Dellacasa, F. Prino, R. Shahoyan, S. Silva, L. Ramello, M. Gonin, N. De Marco, I. Ropotar, M.B. Golubeva, N. Willis, L. Kluberg, T.L. Karavitcheva, M. Monteno, S. Dita, M. Mac Cormick, S Mehrabyan, Bruno Alessandro, Enrico Scomparin, B. Espagnon, A. De Falco, B. Cheynis, A. Bussiere, S. Mourgues, L. Capelli, N.S. Topilskaya, F.F. Guber, D. Jouan, P. Saturnini, M. Gallio, P. Sonderegger, João Cruz, S. Ramos, R. Haroutunian, T. Chambon, Y. Le Bornec, A. Musso, G.L. Usai, L. Riccati, C. Cicalò, C. Quintans, M. Atayan, J.Y. Grossiord, Yu.K. Gavrilov, R. Arnaldi, J. Fargeix, N. Constans, A. Marzari-Chiesa, M. Sitta, J. Castor, S. Serci, A. Baldit, E. Vercellin, M. Masera, C. Baglin, P. Rato-Mendes, P. Macciotta, E. Chiavassa, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), NA50, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, 010308 nuclear & particles physics, Hadron, Drell–Yan process, 01 natural sciences, Deconfinement, Nuclear physics, Strange matter, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Quark–gluon plasma, High Energy Physics::Experiment, Color confinement, Nuclear Experiment, 010306 general physics, Particle Physics - Experiment, Production rate
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/$\psi$ anomalous suppression. This new measurement, besides providing a deeper understanding of the previous observations, reveals a steady significative decrease in the J/$\psi$ production rate up to the most central Pb-Pb collisions. It clearly rules out the presently available conventional (hadronic) models of J/$\psi$ suppression, which unanimously predict a saturation of the J/$\psi$ 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.
Published: 2000
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45. Searching for QGP: the J/ψ probe in the NA50/CERN experiment

Author: S. Silva, Brigitte Cheynis, X. Tarrago, M.P. Comets, Ermanno Vercellin, L. Riccati, Y.K. Gavrilov, T. Chambon, Alexey Kurepin, A. Piccotti, Paolo Giubellino, P. Rato Mendes, M. Gallio, J.-Y. Grossiord, J. Fargeix, B. Chaurand, O. Drapier, A. Baldit, M. Masera, C. Gerschel, R. Haroutunian, A. Marzari-Chiesa, C. Baglin, S. Serci, A. Guichard, G. Dellacasa, M. Gonin, M. Bedjidian, F.F. Guber, S. Ramos, Luciano Ramello, G. L. Usai, P. Bordalo, R. Hakobyan, G. Puddu, N. De Marco, Bruno Espagnon, F. Prino, A. Musso, P. Force, A. Devaux, Laurent Ducroux, Serban Constantinescu, A. De Falco, C. Cicalo, I. Chevrot, P. Petiau, I. Ropotar, N. Willis, Ruben Shahoyan, V. Boldea, Roberta Arnaldi, Enrico Scomparin, Marco Monteno, P. Sonderegger, S. Beole, A.A. Grigorian, A. Bussiere, P. Saturnini, M. Mac Cormick, Marek Idzik, P. Macciotta, T. Claudino, Bruno Alessandro, L. Capelli, H.R. Gulkanyan, C. Soave, Mario Sitta, J. Castor, N. Constans, M.B. Golubeva, Sanda Dita, D. Jouan, Alberto Masoni, L. Villatte, S. Mehrabyan, L. Casagrande, A. Romana, Y. Le Bornec, Calin Alexa, J.-R. Pizzi, E. Chiavassa, Carlos Lourenco, L. Kluberg, N.S. Topilskaya, C. Quintans, M. Atayan, M.C. Abreu, and T.L. Karavitcheva
Subjects: Physics, Particle physics, Large Hadron Collider, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Hadron, Phase (waves), Function (mathematics), Curvature, J/psi meson, Nuclear physics, Quark–gluon plasma, High Energy Physics::Experiment, Nuclear Experiment
Abstract: The J/ψ production in 158 A GeV Pb-Pb interactions is studied as a function of centrality. Its pattern, after a first sharp variation around ET=40 GeV, continues to fall down and exhibits a curvature change around ET=90 GeV. This trend excludes any conventional hadronic model and is in agreement with a deconfined quark-gluon phase scenario.
Published: 2000
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46. The elliptic flow of neutral transverse energy in heavy ion interactions at SPS energies

Author: P. Sonderegger, S. Filippov, F.F. Guber, Paolo Giubellino, Corrado Cicalo, M.C. Abreu, A. De Falco, T.L. Karavitcheva, Carlos Lourenco, S. Mourgues, Roberta Arnaldi, J. Astruc, R. Haroutunian, L. Kluberg, N.S. Topilskaya, V. Caponi, I. Ropotar, Stefania Beole, R. Shaboyan, François Fleuret, Y.K. Gavrilov, G. Dellacasa, O. Drapier, T. Chambon, Laurent Ducroux, P. Force, X. Tarrago, Ermanno Vercellin, C. Quintans, M. Atayan, N. Willis, A. Devaux, Massimo Masera, W.L. Prado da Silva, J.-R. Pizzi, L. Villatte, M. P. Comets, B. Chaurand, J.-Y. Grossiord, M. Mac Cormick, A. Guichard, L. Riccati, I. Chevrot, Mauro Gallio, A. Bussiere, V. Boldea, L. Ramello, João Cruz, C. Racca, B. Espagnon, C. Gerschel, G. Puddu, S. Ramos, F. Bellaiche, M.B. Golubeva, A. Marzari-Chiesa, Marco Monteno, E. Chiavassa, G. L. Usai, F. Ohlsson-Malek, Y. Le Bornec, C. Baglin, A. Romana, P. Rato-Mendes, J. Castor, P. Macciotta, J. Fargeix, Marek Idzik, L. Capelli, A.A. Grigorian, A. Piccotti, P. Bordalo, R. Hakobyan, M. Bedjidian, Pierre Saturnini, A. Musso, Sanda Dita, D. Jouan, A. Baldit, Serban Constantinescu, A. Masoni, N. Constans, Enrico Scomparin, Bruno Alessandro, M. Gonin, Calin Alexa, H.R. Gulkanyan, C. Soave, S. Mehrabyan, A. B. Kurepin, S. Silva, Brigitte Cheynis, Mario Sitta, L. Casagrande, Sergio Serci, N. De Marco, P. Petiau, Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), NA50, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL)
Subjects: Physics, Nuclear and High Energy Physics, Phase transition, Meson, 010308 nuclear & particles physics, Elliptic flow, Hadron, Elementary particle, Kinetic energy, Quarkonium, 01 natural sciences, 7. Clean energy, Nuclear physics, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Atomic physics, Impact parameter, Nuclear Experiment, 010306 general physics
Abstract: The threshold effect in the J/ψ suppression seen in the NA50 data in lead on lead interactions at the CERN SPS [1,2] can't be taken into account by conventional models. Other candidate models [3] use a phase transition, and therefore let suppose that the thermodynamic variables are defined everywhere that is the so-called thermalization. The in-plane elliptic flow, which has been proposed [4] in order to probe the thermalization at these beam energies, is found to be actually present in lead on lead interactions at 158A GeV/ c , but can't be observed in sulphur on sulphur at 200A GeV/ c in the NA38 data [5,6].
Published: 1999

47. Dimuon enhancement in nucleus-nucleus ultrarelativistic interactions

Author: Mario Sitta, J. Astruc, M. Gonin, F. Bellaiche, C. Baglin, S. Mehrabyan, Y.K. Gavrilov, P. Saturnini, P. Rato-Mendes, H.R. Gulkanyan, B. Cheynis, X. Tarrago, J. R. Pizzi, Paolo Giubellino, C. Soave, N. Constans, C. Gerschel, A. Baldit, C. Racca, R. Kossakowski, L. Villatte, J. Cruz, Mauro Gallio, V. Boldea, S. Silva, Stefania Beole, Bruno Alessandro, M. P. Comets, A. Romana, S. Serci, R. Hakobyan, P. Macciotta, François Fleuret, G. Puddu, A. Marzari-Chiesa, B. Chaurand, C. Cicalo, B. Espagnon, E. Scomparin, I. Chevrot, L. Kluberg, N.S. Topilskaya, C. Lourenço, L. Luquin, A. Guichard, Ruben Shahoyan, L. Capelli, G. L. Usai, P. Bordalo, L. Riccati, N. De Marco, L. Casagrande, A. Devaux, E. Chiavassa, J. Castor, S. Dita, P. Force, O. Drapier, R. Haroutunian, E. Vercellin, Laurent Ducroux, M. Mac Cormick, D. Jouan, A. Musso, A. Bussiere, I. Ropotar, V. Caponi, Y. Le Bornec, T. Chambon, Calin Alexa, A.A. Grigorian, S. Ramos, Didier Contardo, G. Dellacasa, A. Piccotti, C. Quintans, M. Atayan, M. Masera, S.N. Filippov, F. Ohlsson-Malek, S. Mourgues, W.L. Prado da Silva, M.C. Abreu, M.B. Golubeva, M. Idzik, R. Ferreira, T.L. Karavitcheva, R. Mandry, A. Bohrani, M. Monteno, M. Bedjidian, S. Constantinescu, F.F. Guber, P. Sonderegger, Luciano Ramello, Ab Kurepin, J. Varela, Alberto Masoni, P. Petiau, J.-Y. Grossiord, J. Fargeix, G. Landau, A. De Falco, Roberta Arnaldi, Ph. Gorodetzky, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire Leprince-Ringuet (LLR), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), NA38, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Robert, Suzanne, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), and Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Muon, Meson, High Energy Physics::Phenomenology, Nuclear Theory, Nuclear physics, [PHYS.HPHE] Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Superposition principle, medicine.anatomical_structure, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Mass spectrum, medicine, High Energy Physics::Experiment, Nucleon, Nuclear Experiment, Nucleus, Particle Physics - Experiment
Abstract: The study of muon pairs in the mass region $1.5
Published: 1999

48. Latest results from NA50 on J/ψ suppression in Pb-Pb collisions

Author: V. Caponi, Alberto Masoni, Mario Sitta, C. Quintans, M. Atayan, S. Mourgues, Roberta Arnaldi, Bruno Alessandro, A. Bussiere, A. Romana, Calin Alexa, Laurent Ducroux, Paolo Giubellino, Marco Monteno, T. Chambon, Ermanno Vercellin, F.F. Guber, Enrico Scomparin, Y. Le Bornec, Carlos Lourenco, L. Kluberg, A. Piccotti, M. Gonin, E. Chiavassa, N.S. Topilskaya, A.A. Grigorian, X. Tarrago, Marek Idzik, M. Masera, H.R. Gulkanyan, C. Soave, Luciano Ramello, J. Astruc, Y.K. Gavrilov, J.-R. Pizzi, B. Chaurand, Sanda Dita, D. Jouan, P. Force, J.-Y. Grossiord, L. Casagrande, S. Serci, G. Puddu, C. Gerschel, João Cruz, Alexey Kurepin, I. Ropotar, M.B. Golubeva, S. Mehrabyan, P. Bordalo, V. Boldea, J. Castor, R. Haroutunian, R. Hakobyan, M. Mac Cormick, F. Ohlsson-Malek, G. Dellacasa, A. Baldit, Serban Constantinescu, N. Willis, L. Capelli, M. P. Comets, L. Riccati, A. Guichard, I. Chevrot, N. De Marco, L. Villatte, A. Devaux, F. Bellaiche, A. Marzari-Chiesa, C. Racca, Corrado Cicalo, S. Beole, M.C. Abreu, S. Ramos, T.L. Karavitcheva, W. L. Prado Da Silva, B. Espagnon, O. Drapier, A. De Falco, P. Saturnini, P. Petiau, N. Constans, P. Sonderegger, S. Filippov, M. Bedjidian, J. Fargeix, A. Musso, G. L. Usai, Ruben Shahoyan, C. Baglin, P. Rato-Mendes, P. Macciotta, M. Gallio, François Fleuret, S. Silva, and Brigitte Cheynis
Subjects: Event selection, Physics, Nuclear physics, Nuclear and High Energy Physics, Transverse plane, Particle physics, Large Hadron Collider, Nuclear Experiment, Nucleon, Collision, Electromagnetic radiation, Central region
Abstract: The main goal of the NA50 experiment is to study the J/ψ suppression pattern in Pb-Pb interactions, at 158 GeV/c per nucleon at the CERN SPS. We present here the results from the 1996 (final) and 1998 (preliminary) data taking periods. They confirm and extend our previous observation that the J/ψ is anomalously suppressed from peripheral to central collisions. With new event selection procedures and different analysis techniques, we observe that in peripheral collisions the J/ψ cross section per nucleon-nucleon collision agrees with the pattern inferred from a wide range of measurements with lighter systems, from pp up to S-U. When the collisions become more central a clear departure from this behaviour is observed. The 1996 data show a sudden drop in the J/ψ production yield for ET values above 40 GeV, where ET is the neutral transverse electromagnetic energy released in the colision and measured in the EM calorimeter. The 1998 data provide a big improvement in the study of the most central region, where a second change in the pattern becomes visible.
Published: 1999

49. Observation of fission in Pb-Pb interactions at 158A GeV

Author: A. Romana, Calin Alexa, Ermanno Vercellin, J.-R. Pizzi, L. Bardi, W.L. Prado da Silva, I. Chevrot, G. Landaud, F. Ohlsson-Malek, G. L. Usai, A. Defalco, Marco Monteno, Y. Lebornec, A. Piccotti, G. Dellacasa, H.R. Gulkanyan, C. Soave, Paolo Giubellino, Mauro Gallio, V. Boldea, L. Casagrande, S. Silva, J.-Y. Grossiord, C. Vale, A. Baldit, Brigitte Cheynis, Alberto Masoni, N. Willis, S. Mourgues, E. Chiavassa, Marek Idzik, G. Puddu, Bruno Alessandro, M. Masera, Ruben Shahoyan, S. Mehrabyan, T. Chambon, S. Serci, M.P. Comets, B. Espagnon, Pietro Cortese, A. Marzari-Chiesa, A. Guichard, Roberta Arnaldi, S. Ramos, X. Tarrago, F. Bellaiche, João Cruz, Y.K. Gavrilov, J. Castor, Corrado Cicalo, Alexey Kurepin, Sanda Dita, D. Jouan, O. Drapier, P. Petiau, Enrico Scomparin, C. Baglin, L. Luquin, Mario Sitta, M. Gonin, S. Beole, P. Rato-Mendes, I. Ropotar, M. Maccormick, Carlos Lourenco, A.A. Grigorian, P. Sonderegger, A. Bussiere, P. Saturnini, L. Kluberg, N.S. Topilskaya, R. Haroutunian, M.C. Abreu, L. Riccati, T.L. Karavitcheva, P. Force, J. Fargeix, M. Bedjidian, M.B. Golubeva, C. Quintans, M. Atayan, C. Racca, François Fleuret, P. Bordalo, R. Hakobyan, Serban Constantinescu, A. Devaux, A. Musso, F.F. Guber, M. P. Macciotta, Luciano Ramello, B. Chaurand, J. Astruc, C. Gerschel, and N DeMarco
Subjects: Physics, Nuclear and High Energy Physics, Cluster decay, Large Hadron Collider, 010308 nuclear & particles physics, Fission, Nuclear Theory, Detector, Charge (physics), 01 natural sciences, Calorimeter, Nuclear physics, Yield (chemistry), 0103 physical sciences, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment, 010306 general physics, Beam (structure)
Abstract: The NA50 experiment at the CERN SPS has been equipped with a Cerenkov quartz detector to measure the charge of projectilelike fragments emitted in interactions of the lead beam of $158A \mathrm{GeV}$ with a 12 mm thick lead target. A clear fission peak has been observed in the light output distribution of the fragment detector and the measured number of fission events per incident Pb ion is $(1.26\ifmmode\pm\else\textpm\fi{}0.16)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}.$ The information provided by the NA50 zero-degree calorimeter has allowed us to check that fission occurs in extremely peripheral collisions. To provide the first information about the fission mechanism, the expected yield of electromagnetic fission events in our experimental conditions has been computed: it turns out to be about $40%$ smaller than the observed one. The approximations necessarily made in our calculation as well as the contribution due to fission induced by nuclear interaction could account for such a difference.
Published: 1999

50. A test pixel vertex spectrometer to complement the NA50 dimuon spectrometer

Author: S. Mourgues, B. Espagnon, Eugenio Cantatore, P. Bordalo, C. Quintans, M. Atayan, I. Ropotar, R. Hakobyan, H.R. Gulkanyan, A. Guichard, A.M Mayevskaya, M. Campbell, M.C. Abreu, T.L. Karavitcheva, Erik H.M. Heijne, A. Baldisseri, Y.K. Gavrilov, João Cruz, A. Devaux, S. Ramos, F.F. Guber, Alexey Kurepin, A.A. Grigorian, V Danielyan, S. Mehrabyan, R. Haroutunian, S.N. Filippov, J.-Y. Grossiord, Carlos Lourenco, N.S. Topilskaya, H. Vardanyan, J.-R. Pizzi, O. Drapier, F. Staley, Laurent Ducroux, A. Baldit, J Gosset, P. Force, E. Chesi, J. Castor, P. Sonderegger, Walter Snoeys, P. Saturnini, Y Terrien, I. Chevrot, L. Casagrande, H Borel, M. Bedjidian, J. Fargeix, C. Baglin, S. Silva, Brigitte Cheynis, T. Chambon, Ruben Shahoyan, A. Bussiere, M.B. Golubeva, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), ALICE, Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), NA50, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL)
Subjects: Physics, Nuclear and High Energy Physics, Vertex (computer graphics), Muon, Pixel, Spectrometer, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Nuclear Theory, Tracking (particle physics), 01 natural sciences, Particle detector, Charged particle, Nuclear physics, 0103 physical sciences, Measuring instrument, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment, 010306 general physics, Instrumentation
Abstract: We have simulated the performance of a magnetic pixel vertex spectrometer, to be installed in the target area of the NA50 dimuon spectrometer. It performs well in tracking hundreds of charged particles emitted in head-on Pb–Pb collisions. The two muons among them are identified by matching their parameters to those of the muons identified in the NA50 spectrometer. A test setup of 66 000 pixels has been built. Results from a p–Be test run are presented.
Published: 1998

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