Author: "Kluberg, L." / Topic: nuclear experiment - Searchworks@Jio Institute Digital Library Search Results

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64 results on '"Kluberg, L."'

1. Nuclear dependence of light neutral meson production in p-A collisions at 400 GeV with NA60

Author: Arnaldi, R., Banicz, K., Borer, K., Castor, J., Chaurand, B., Chen, W., Cicalò, C., Colla, A., Cortese, P., Damjanovic, S., David, A., De Falco, A., Devaux, A., Ducroux, L., En'yo, H., Fargeix, J., Ferretti, A., Floris, M., Förster, A., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J. M., Jarron, P., Keil, M., Kluberg, L., Li, Z., Lourenço, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P., Poghosyan, T., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H. J., Tieulent, R., Uras, A., Usai, G., Veenhof, R., and Wöhri, H. K.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: The NA60 experiment has studied low-mass muon pair production in proton-nucleus collisions with a system of Be, Cu, In, W, Pb and U targets, using a 400 GeV proton beam at the CERN SPS. The transverse momentum spectra of the $\rho/\omega$ and $\phi$ mesons are measured in the full $p_\mathrm{T}$ range accessible, from $p_\mathrm{T} = 0$ up to 2 GeV/$c$. The nuclear dependence of the production cross sections of the $\eta$, $\omega$ and $\phi$ mesons has been found to be consistent with the power law $\sigma_\mathrm{pA} \propto \mathrm{A}^\alpha$, with the $\alpha$ parameter increasing as a function of $p_\mathrm{T}$ for all the particles, and an approximate hierarchy $\alpha_\eta \approx \alpha_\phi > \alpha_\omega$. The cross section ratios $\sigma_\eta/\sigma_\omega$, $\sigma_\rho/\sigma_\omega$ and $\sigma_\phi/\sigma_\omega$ have been studied as a function of the size A of the production target, and an increase of the $\eta$ and $\phi$ yields relative to the $\omega$ is observed from p-Be to p-U collisions.
Published: 2020
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2. NA60 results on thermal dimuons

Author: NA60 Collaboration, Arnaldi, R., Banicz, K., Borer, K., Castor, J., Chaurand, B., Chen, W., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., David, A., de Falco, A., Devaux, A., Ducroux, L., En'yo, H., Fargeix, J., Ferretti, A., Floris, M., Foerster, A., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J. M., Keil, M., Kluberg, L., Li, Z., Lourenco, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P., Poghosyan, T., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H. J., Tieulent, R., Usai, G., Veenhof, R., and Woehri, H. K.
Subjects: Nuclear Experiment
Abstract: The NA60 experiment at the CERN SPS has measured muon pairs with unprecedented precision in 158A GeV In-In collisions. A strong excess of pairs above the known sources is observed in the whole mass region 0.2 rho -> mu+mu- annihilation. The associated rho spectral function shows a strong broadening, but essentially no shift in mass. For M>1 GeV, the excess is found to be prompt, not due to enhanced charm production, with pronounced differences to Drell-Yan pairs. The slope parameter Teff associated with the transverse momentum spectra rises with mass up to the rho, followed by a sudden decline above. The rise for M<1 GeV is consistent with radial flow of a hadronic emission source. The seeming absence of significant flow for M>1 GeV and its relation to parton-hadron duality is discussed in detail, suggesting a dominantly partonic emission source in this region. A comparison of the data to the present status of theoretical modeling is also contained. The accumulated empirical evidence, including also a Planck-like shape of the mass spectra at low pT and the lack of polarization, is consistent with a global interpretation of the excess dimuons as thermal radiation. We conclude with first results on omega in-medium effects., Comment: 10 pages, 12 figures, submitted to Eur. Phys. J. C
Published: 2008
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3. First results on angular distributions of thermal dileptons in nuclear collisions

Author: NA60 Collaboration, Arnaldi, R., Banicz, K., Borer, K., Castor, J., Chaurand, B., Chen, W., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., David, A., de Falco, A., Devaux, A., Ducroux, L., En'yo, H., Fargeix, J., Ferretti, A., Floris, M., Foerster, A., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J. M., Keil, M., Kluberg, L., Li, Z., Lourenco, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P., Poghosyan, T., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H. J., Tieulent, R., Usai, G., Veenhof, R., and Woehri, H. K.
Subjects: Nuclear Experiment
Abstract: The NA60 experiment at the CERN SPS has studied dimuon production in 158A GeV In-In collisions. The strong excess of pairs above the known sources found in the complete mass region 0.2
Published: 2008
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4. Evidence for the production of thermal muon pairs with masses above 1 GeV/c^2 in 158A GeV Indium-Indium Collisions

Author: NA60 Collaboration, Arnaldi, R., Banicz, K., Borer, K., Castor, J., Chaurand, B., Chen, W., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., David, A., de Falco, A., Devaux, A., Ducroux, L., Enyo, H., Fargeix, J., Ferretti, A., Floris, M., Forster, A., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J. M., Keil, M., Kluberg, L., Li, Z., Lourenco, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P., Poghosyan, T., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H. J., Tieulent, R., Usai, G., Veenhof, R., and Wohri, H. K.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: The yield of muon pairs in the invariant mass region 1
Published: 2008
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5. Highlights from the NA60 experiment

Author: Ferretti, A., Arnaldi, R., Averbeck, R., Banicz, K., Castor, J., Chaurand, B., Cicalò, C., Colla, A., Cortese, P., Damjanovic, S., David, A., De Falco, A., Devaux, A., Drees, A., Ducroux, L., En'yo, H., Floris, M., Förster, A., Force, P., Guettet, N., Guichard, A., Gulkanyan, H., Heuser, J. M., Keil, M., Kluberg, L., Lourenço, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H. J., Tieulent, R., Usai, G., Veenhof, R., and Wöhri, H.
Subjects: Nuclear Experiment
Abstract: The NA60 experiment is a fixed-target experiment at the CERN SPS. It has measured the dimuon yield in Indium--Indium collisions with an In beam of 158 AGeV/c and in p-A collisions with a proton beam of 400 and 158 AGeV/c. The results allow to address three important physics topics, namely the study of the rho spectral function in nuclear collisions, the clarification of the origin of the dimuon excess measured by NA50 in the intermediate mass range, and the J/psi suppression pattern in a collision system different from Pb-Pb. An overview of these results will be given in this paper., Comment: 4 pages, 6 figures, proceeding for the Rencontres de Moriond - QCD and Hadronic interactions - La Thuile (Italy), March 17-24 2007
Published: 2007

6. J/$\psi$ suppression in In-In collisions at 158 GeV/nucleon

Author: Arnaldi, R., Arnaldi, NA60 Collaboration R., Averbeck, R., Banicz, K., Castor, J., Chaurand, B., Cicalo', C., Colla, A., Cortese, P., Damjanovic, S., David, A., DeFalco, A., Devaux, A., Drees, A., Ducroux, L., En'yo, H., Ferretti, A., Floris, M., Forster, A., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Lourenco, C., Lozano, J., Manso, F., Masoni, A., Martins, P., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H. J., Tieulent, R., Usai, G., Veenhof, R., and Wohri, H. K.
Subjects: Nuclear Experiment
Abstract: The NA60 experiment has studied J/$\psi$ production in Indium-Indium collisions at 158 A$\cdot$GeV. In this paper we present an updated set of results obtained with the complete set of available statistics and an improved alignment of the vertex tracker. The centrality dependence of the J/$\psi$ production, obtained with an analysis technique based only on the J/$\psi$ sample, indicates that a suppression beyond that induced by nuclear absorption is present in In-In collisions, setting in at $\sim$80 participant nucleons. A first study of the systematic errors related with this measurement is discussed. We also present preliminary results on the J/$\psi$ azimuthal distributions., Comment: 8 pages, 3 figures, proceedings of Hard Probes 2006 International Conference
Published: 2007
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7. Low Mass Dimuon Production in Indium-Indium Collisions at the CERN SPS

Author: NA60 Collaboration, Floris, M., Arnaldi, R., Averbeck, R., Banicz, K., Castor, J., Chaurand, B., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., David, A., de Falco, A., Devaux, A., Dress, A., Ducroux, L., Farjeix, J., En'yo, H., Ferretti, A., Förster, A., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Lozano, J., Lourenço, C., Manso, F., Masoni, A., Martins, P., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H. J., Tieulent, R., Usai, G., Veenhof, R., and Wöhri, H. K.
Subjects: Nuclear Experiment
Abstract: NA60 is a fixed-target experiment at the CERN SPS which measured dimuon production in nucleus-nucleus and proton-nucleus collisions. In this paper we report on a precision measurement of low-mass muon pairs in 158 AGeV indium-indium collisions. A significant excess of pairs is observed above the yield expected from neutral meson decays. The excess can be isolated by subtraction of expected sources, thanks to the excellent mass resolution and large sample size., Comment: 4 pages, 3 figures, Contribution at XLIst Rencontres de Moriond, "QCD and High Energy Hadronic Interactions"
Published: 2006

8. Precision study of the $\eta \to \mu \mu \gamma$ and $\omega \to \mu + \mu \mu \pi^0$ electromagnetic transition form-factors and of the $\rho \to \mu \mu$ line shape in NA60

Author: Arnaldi, R., Banicz, K., Borer, K., Castor, J., Chaurand, B., Chen, W., Cicalò, C., Colla, A., Cortese, P., Damjanovic, S., David, A., de Falco, A., Devaux, A., Ducroux, L., En'yo, H., Fargeix, J., Ferretti, A., Floris, M., Förster, A., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J.M., Jarron, P., Keil, M., Kluberg, L., Li, Z., Lourenço, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P., Poghosyan, T., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H.J., Tieulent, R., Uras, A., Usai, G., Veenhof, R., and Wöhri, H.K.
Subjects: High Energy Physics::Experiment, Nuclear Physics - Experiment, Nuclear Experiment, High Energy Physics - Experiment
Abstract: The NA60 experiment studied low-mass muon pair production in proton–nucleus (p–A) collisions using a 400 GeV proton beam at the CERN SPS. The low-mass dimuon spectrum is well described by the superposition of the two-body and Dalitz decays of the light neutral mesons η , ρ , ω , η′ and ϕ , and no evidence of in-medium effects is found. A new high-precision measurement of the electromagnetic transition form factors of the η and ω was performed, profiting from a 10 times larger data sample than the peripheral In–In sample previously collected by NA60. Using the pole-parameterisation |F(M)|2=(1−M2/Λ2)−2 we find Λη−2=1.934±0.067 (stat.) ±0.050 (syst.) (GeV/c2)−2 and Λω−2=2.223±0.026 (stat.) ±0.037 (syst.) (GeV/c2)−2 . An improved value of the branching ratio of the Dalitz decay ω→μ+μ−π0 is also obtained, with BR(ω→μ+μ−π0)=[1.41±0.09 (stat.)±0.15 (syst.)]×10−4 . Further results refer to the ρ line shape and a new limit on ρ/ω interference in hadron interactions. The NA60 experiment studied low-mass muon pair production in proton-nucleus (p-A) collisions using a 400~GeV proton beam at the CERN SPS. The low-mass dimuon spectrum is well described by the superposition of the two-body and Dalitz decays of the light neutral mesons $\eta$, $\rho$, $\omega$, $\eta'$ and $\phi$, and no evidence of in-medium effects is found. A new high-precision measurement of the electromagnetic transition form factors of the $\eta$ and $\omega$ was performed, profiting from a 10~times larger data sample than the peripheral In-In sample previously collected by NA60. Using the pole-parameterisation $|F(M)|^2 = (1 -M^2/\mathrm{\Lambda}^2)^{-2}$ we find $\mathrm{\Lambda}_\eta^{-2} = 1.934\ \pm\ 0.067$~(stat.) $\pm\ 0.050$~(syst.)~(GeV/$c^2$)$^{-2}$ and $\mathrm{\Lambda}_\omega^{-2} = 2.223\ \pm\ 0.026$~(stat.) $\pm\ 0.037$~(syst.)~(GeV/$c^2$)$^{-2}$. An improved value of the branching ratio of the Dalitz decay $\omega \to \mu^+\mu^-\pi^0$ is also obtained, with $BR(\omega \to \mu^+\mu^-\pi^0) = [1.41~\pm~0.09~\mathrm{(stat.)}$ $\pm~0.15~\mathrm{(syst.)}] \times 10^{-4}$. Further results refer to the $\rho$ line shape and a new limit on $\rho/\omega$ interference in hadron interactions.
Published: 2016

9. Low mass dimuon production in Indium-Indium collisions at 158 A GeV

Author: Usai, G, Arnaldi, R, Averbeck, R, Banicz, K, Castor, J, Chaurand, B, Cicalo, C, Colla, A, Cortese, P, Damjanovic, S, David, A, DE FALCO, A, Devaux, A, Drees, A, Ducroux, L, En'Yo, H, Ferretti, Alessandro, Floris, M, Force, P, Guettet, N, Guichard, A, Gulkanian, H, Heuser, J, Keil, M, Kluberg, L, Lozano, J, Lourenco, C, Manso, F, Masoni, A, Martins, P, Neves, A, Ohnishi, H, Oppedisano, C, Parracho, P, Pillot, P, Puddu, G, Radermacher, E, Ramalhete, P, Rosinsky, P, Scomparin, E, Seixas, J, Serci, S, Shahoyan, R, Sonderegger, P, Specht, Hj, Tieulent, R, Veenhof, R, Wohri, Hk, 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), 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 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), NA60, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), 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)
Subjects: Physics, Particle physics, Large Hadron Collider, Physics and Astronomy (miscellaneous), 010308 nuclear & particles physics, Nuclear Theory, chemistry.chemical_element, 01 natural sciences, Nuclear physics, chemistry, 0103 physical sciences, Transverse momentum, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, Open charm, Nuclear Experiment, Nucleon, Low Mass, 010303 astronomy & astrophysics, Engineering (miscellaneous), Indium
Abstract: NA60; The NA60 experiment studies open charm and prompt dimuon production in proton-nucleus and nucleus-nucleus collisions at the CERN SPS. During 2003 the experiment collected data in Indium-Indium collisions at 158 GeV per nucleon. Almost 240 million dimuon events were recorded. New results on J/$\psi$ suppression, open-charm production and low mass dimuons should help clarify some interesting questions left open by previous experiments. After a brief detector description, this paper focuses on the analysis of the low mass dimuons. Preliminary results are presented on the $\theta/\omega$ production cross section ratios and on the $\theta$ transverse momentum distributions, both as a function of collisions centrality.
Published: 2005

10. Highlights from NA60

Author: De Falco, A., Arnaldi, R., Banicz, K., Borer, K., Castor, J., Chaurand, B., Chen, W., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., David, A., Devaux, A., Ducroux, L., En'yo, H., Fargeix, J., Ferretti, A., Floris, M., Force, P., Forster, A., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Li, Z., Louren��o, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P., Poghosyan, T., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H. J., Tieulent, R., Usai, G., Veenhof, R., and W��hri, H.
Subjects: High Energy Physics - Experiment (hep-ex), Nuclear Theory, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment
Abstract: NA60 measured dimuon production in p-A and In-In collisions at the CERN SPS. This paper presents a high statistics measurement of $��$ meson production in In-In collisions at 158 AGeV. Both the transverse momentum, rapidity, decay angular distributions and the absolute yield were measured as a function of centrality. The results are compared to previous measurements in order to shed light on the long standing $��$ puzzle. In addition, highlights on $��$ meson production and on the dimuon excess below the J/$��$ mass are presented., 8 pages, 6 figures, proceedings of the Strangeness in Quark Matter 2008 conference (SQM08), Beijing, Oct.6-10, 2008
Published: 2009
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11. phi Production in In-In Collisions at 158-A-GeV

Author: Arnaldi, R., Banicz, K., Borer, K., Castor, J., Chaurand, B., Chen, W., Cicalò, C., Colla, A., Cortese, P., Damjanovic, S., David, A., de Falco, A., Devaux, A., Ducroux, L., En’yo, H., Fargeix, J., Ferretti, A., Floris, M., Förster, A., Force, P., Guettet, N., Guichard, A., Gulkanyan, H., Heuser, J., Keil, M., Kluberg, L., Li, Z., Lourenço, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P., Poghosyan, T., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H. J., Tieulent, R., Uras, A., Usai, G., Veenhof, R., Wöhri, H. K., 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), NA60, Université Claude Bernard Lyon 1 (UCBL), 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)
Subjects: NA60, Particle physics, SPS ENERGIES, Physics and Astronomy (miscellaneous), MESON PRODUCTION, STRANGENESS, INDIUM-INDIUM COLLISIONS, HEAVY-ION COLLISIONS, 01 natural sciences, Spectral line, High Energy Physics - Experiment, QUARK-GLUON PLASMA, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], DETECTORS, Rapidity, 010306 general physics, Nuclear Experiment, NUCLEON, Engineering (miscellaneous), Physics, Muon, Large Hadron Collider, RADIATION, 010308 nuclear & particles physics, Coupling (probability), Pair production, High Energy Physics::Experiment, Centrality, Particle Physics - Experiment, Energy (signal processing)
Abstract: The NA60 experiment has measured muon pair production in In-In collisions at 158 AGeV at the CERN SPS. This paper presents a high statistics measurement of $\phi\to\mu\mu$ meson production. Differential spectra, yields, mass and width are measured as a function of centrality and compared to previous measurements in other colliding systems at the same energy. The width of the rapidity distribution is found to be constant as a function of centrality, compatible with previous results. The decay muon polar angle distribution is measured in several reference frames. No evidence of polarization is found as a function of transverse momentum and centrality. The analysis of the $p_{T}$ spectra shows that the $\phi$ has a small radial flow, implying a weak coupling to the medium. The $T_{eff}$ parameter measured in In-In collisions suggests that the high value observed in Pb-Pb in the kaon channel is difficult to reconcile with radial flow alone. The absolute yield is compared to results in Pb-Pb collisions: though significantly smaller than measured by NA50 in the muon channel, it is found to exceed the NA49 and CERES data in the kaon channel at any centrality. The mass and width are found to be compatible with the PDG values at any centrality and at any $p_{T}$: no evidence for in-medium modifications is observed., Comment: 18 pages, 18 figures, accepted for publication in EPJ C
Published: 2009

12. Study of the electromagnetic transition form-factors in \eta -> \mu^+\mu^-\gamma and \omega -> \mu^+\mu^-\pi^0 decays with NA60

Author: Arnaldi, R., Banicz, K., Castor, J., Chaurand, B., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., Andre, David, de Falco, A., Devaux, A., Ducroux, L., Enyo, H., Fargeix, J., Ferretti, Alessandro, Floris, M., Force, P., Forster, A., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P., Poghosyan, T., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H. J., Tieulent, R., Usai, G., Veenhof, R., Wohri, H., 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), 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), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: Lepton pairs, Transition form factor, Conversion decays, High Energy Physics - Phenomenology, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Phenomenology
Abstract: The NA60 experiment at the CERN SPS has studied low-mass muon pairs in 158A GeV In-In collisions. The mass and pT spectra associated with peripheral collisions can quantitatively be described by the known neutral meson decays. The high data quality has allowed to remeasure the electromagnetic transition form factors of the Dalitz decays \eta -> \mu^+\mu^-\gamma and \omega -> \mu^+\mu^-\pi^0. Using the usual pole approximation F = (1-M_{\mu\mu}^{2}/\Lambda^{2})^{-1} for the form factors, we find \Lambda^{-2} (in GeV^{-2}) to be 1.95+-0.17(stat.)+-0.05(syst.) for the \eta and 2.24+-0.06(stat.)+-0.02(syst.) for the \omega. While the values agree with previous results from the Lepton-G experiment, the errors are greatly improved, confirming now on the level of 10\sigma the strong enhancement of the \omega form factor beyond the expectation from vector meson dominance. An improved value of the branching ratio BR(\omega -> \mu^+\mu^-\pi^0) = [1.73+-0.25(stat.)+-0.14(syst.)]*10^{-4} has been obtained as a byproduct., Comment: Submitted to Phys. Lett. B
Published: 2009

13. Evidence for the production of thermal-like muon pairs with masses above 1 GeV/c^2 in 158A GeV Indium-Indium Collisions

Author: NA60 Collaboration, Arnaldi, R., Banicz, K., Borer, K., Castor, J., Chaurand, B., Chen, W., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., David, A., de Falco, A., Devaux, A., Ducroux, L., Enyo, H., Fargeix, J., Ferretti, A., Floris, M., Forster, A., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J. M., Keil, M., Kluberg, L., Li, Z., Lourenco, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P., Poghosyan, T., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H. J., Tieulent, R., Usai, G., Veenhof, R., Wohri, H. K., 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), 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 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), NA60, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), 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)
Subjects: 14.40.Lb - 25.75.Nq - 25.75.Cj, Physics::Instrumentation and Detectors, Computer Science::Information Retrieval, Nuclear Theory, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Physics::Accelerator Physics, Nuclear Physics - Experiment, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract: The yield of muon pairs in the invariant mass region 1, Comment: 16 pages, 19 figures
Published: 2009

14. Thermal Dimuon Emission in In-In at the CERN SPS

Author: Arnaldi, R., Banicz, K., Castor, J., Chaurand, B., Cicalò, C., Colla, A., Cortese, P., Damjanovic, S., David, A., De Falco, A., Devaux, A., Ducroux, L., Enyo, H., Ferretti, J., Fargeix, A., Floris, M., Förster, A., Force, P., Guettet, N., Guichard, A., R. Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Lourenço, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, Philippe, Poghosyan, T., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., J. Specht, H., Tieulent, R., Usai, G., Veenhof, R., K. Wöhri, H., 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), 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), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: presenté par M. Floris, FOS: Physical sciences, Nuclear Physics - Experiment, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: The NA60 experiment at the CERN SPS has studied low-mass dimuon production in 158A GeV In-In collisions. A significant excess of pairs is observed above the yield expected from neutral meson decays, consistent with a dominant contribution from $\pi\pi\to\rho\to\mu\mu$. This paper presents precision results on the mass and transverse momentum spectra of the excess pairs. The space-time averaged rho spectral function associated to the measured mass distribution shows a significant broadening, but essentially no mass shift. The slope parameter $T_{eff}$ extracted from the spectra rises with dimuon mass up to the $\rho$, followed by a sudden decline above. While the initial rise is consistent with the expectations for radial flow of a hadronic decay source, the decline indicates a transition to an emission source with much smaller flow, possibly of partonic origin., Comment: 4 pages, 4 figures, presented at the XLIIIth Rencontres de Moriond
Published: 2008

15. Highlights from NA60

Author: De Falco, A., Arnaldi, R., Banicz, K., Borer, K., Castor, J., Chaurand, B., Chen, W., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., David, A., Devaux, A., Ducroux, L., En'Yo, H., Fargeix, J., Ferretti, A., Floris, M., Force, P., Forster, A., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Li, Zhenyu, Lourenço, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, Philippe, Poghosyan, T., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H. J., Tieulent, R., Usai, G., Veenhof, R., Wöhri, H., 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), 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), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: Nuclear Theory, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment, High Energy Physics - Experiment
Abstract: NA60 measured dimuon production in p-A and In-In collisions at the CERN SPS. This paper presents a high statistics measurement of $\phi$ meson production in In-In collisions at 158 AGeV. Both the transverse momentum, rapidity, decay angular distributions and the absolute yield were measured as a function of centrality. The results are compared to previous measurements in order to shed light on the long standing $\phi$ puzzle. In addition, highlights on $\eta$ meson production and on the dimuon excess below the J/$\psi$ mass are presented., Comment: 8 pages, 6 figures, proceedings of the Strangeness in Quark Matter 2008 conference (SQM08), Beijing, Oct.6-10, 2008
Published: 2008

16. Thermal dileptons at SPS energies

Author: Damjanovic, S., Arnaldi, R., Banicz, K., Borer, K., Castor, J., Chaurand, B., Chen, W., Cicalo, C., Colla, A., Cortese, P., David, A., De Falco, A., Devaux, A., Ducroux, L., En'Yo, H., Fargeix, J., Ferretti, A., Floris, M., Foerster, A., Force, P., Guettet, N., Guichard, A., Gulkanian, H., M. Heuser, J., Keil, M., Kluberg, L., Li, Zhenyu, Lourenco, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, Philippe, Poghosyan, T., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., J. Specht, H., Tieulent, R., Usai, G., Veenhof, R., K. Woehri, H., 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), and NA60
Subjects: Physics, Nuclear and High Energy Physics, Annihilation, 010308 nuclear & particles physics, Hadron, FOS: Physical sciences, Radiation, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Polarization (waves), 01 natural sciences, Spectral line, Nuclear physics, Thermal radiation, 0103 physical sciences, Mass spectrum, High Energy Physics::Experiment, Nuclear Physics - Experiment, Charm (quantum number), Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment
Abstract: Clear signs of excess dileptons above the known sources were found at the SPS since long. However, a real clarification of these observations was only recently achieved by NA60, measuring dimuons with unprecedented precision in 158A GeV, In-In collisions. The excess mass spectrum in the region M rho -> mu+mu- annihilation. The associated rho spectral function shows a strong broadening, but essentially no shift in mass. In the region M>1 GeV, the excess is found to be prompt, not due to enhanced charm production. The inverse slope parameter Teff associated with the transverse momentum spectra rises with mass up to the rho, followed by a sudden decline above. While the initial rise, coupled to a hierarchy in hadron freeze-out, points to radial flow of a hadronic decay source, the decline above signals a transition to a low-flow source, presumably of partonic origin. The mass spectra show at low transverse momenta the steep rise towards low masses characteristic for Planck-like radiation. The polarization of the excess referred to the Collins Soper frame is found to be isotropic. All observations are consistent with the interpretation of the excess as thermal radiation., Prepared for 20th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions: Quark Matter 2008 (QM2008), Jaipur, India, 4-10 Feb. 2008
Published: 2008

17. Phi production in In-In collisions and the phi puzzle

Author: Floris, M., Arnaldi, R., Banicz, K., Borer, K., Castor, J., Chaurand, B., Chen, W., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., David, A., de Falco, A., Devaux, A., Ducroux, L., En'Yo, H., Fargeix, J., Ferretti, A., Foerster, A., Force, P., Guettet, N., Guichard, A., Gulkanian, H., M. Heuser, J., Keil, M., Kluberg, L., Li, Zhenyu, Lourenco, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, Philippe, Poghosyan, T., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., J. Specht, H., Tieulent, R., Usai, G., Veenhof, R., K. Woehri, H., 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), and NA60
Subjects: Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: International audience; The NA60 experiment measured dimuon production in In-In collisions at 158 A GeV. This paper presents a high statistics measurement of phi → μμ with the specific objective to provide an insight into the phi puzzle, i.e. the difference in the inverse T slopes and absolute yields measured by NA49 and NA50 in the kaon and lepton channel, respectively. Transverse momentum distributions were studied as a function of centrality. The slope parameter T shows a rapid increase with centrality, followed by a saturation. Variations of T with the fit range of the order of 15 MeV were observerd, possibly as a consequence of radial flow. The phi meson yield normalized to the number of participants increases with centrality and is consistently higher than the yield measured by the NA49 experiment at any centrality
Published: 2008

18. Latest results from NA60

Author: Cortese, P., Arnaldi, R., Banicz, K., Castor, J., Chaurand, B., Cicalo, C., Colla, A., Damjanovic, S., David, A., De Falco, A., Devaux, A., Ducroux, L., Enyo, H., Fargeix, J., Ferretti, A., Floris, M., Forster, A., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J.M., Keil, M., Kluberg, L., Lourenço, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, Philippe, Poghosyan, T., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., J. Specht, H., Tieulent, R., Usai, G., Veenhof, R., K. Wöhri, H., 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), 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), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: Physics, History, Particle physics, Large Hadron Collider, Muon, Meson, 010308 nuclear & particles physics, Nuclear Theory, Hadron, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Quarkonium, 01 natural sciences, Particle identification, Computer Science Applications, Education, Nuclear physics, Pair production, 0103 physical sciences, Invariant mass, High Energy Physics::Experiment, 010306 general physics, Nuclear Experiment
Abstract: International audience; NA60 is a fixed target experiment at the CERN SPS studying dimuon production in different colliding systems: In-In at 158 A·GeV incident energy and p-A collisions at 158 and 400 GeV. A strong excess of dimuon pairs has been observed in the region of the invariant mass spectrum below the J/ψ. The high resolution of the NA60 detector allowed to measure the in-medium modifications of the ρ spectral function and to clarify the origin of the dimuon excess in the region above the phi. The J/ψ suppression has been studied in In-In and p-A collisions at 158 GeV incident energy. The latest results on these topics are addressed in this paper
Published: 2007

19. J/psi production in Indium-Indium collisions at 158 GeV/nucleon

Author: Arnaldi, R., Banicz, K., Castor, J., Chaurand, B., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., David, Andre, de Falco, A., Devaux, A., Ducroux, L., En'yo, H., Fargeix, J., Ferretti, A., Floris, M., Forster, A., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J.M., Keil, M., Kluberg, L., Lourenco, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P., Poghosyan, T., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H.J., Tieulent, R., Usai, G., Veenhof, R., Wohri, H.K., 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), 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), 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), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: Nuclear Theory, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Physics - Experiment, Nuclear Experiment (nucl-ex), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: The NA60 experiment studies muon pair production at the CERN SPS. In this letter we report on a precision measurement of J/psi in In-In collisions. We have studied the J/psi centrality distribution, and we have compared it with the one expected if absorption in cold nuclear matter were the only active suppression mechanism. For collisions involving more than ~80 participant nucleons, we find that an extra suppression is present. This result is in qualitative agreement with previous Pb-Pb measurements by the NA50 experiment, but no theoretical explanation is presently able to coherently describe both results., 5 pages, 1 table, 4 figures, accepted for publication by PRL
Published: 2007

20. NA60 results on the rho spectral function in In-In collisions

Author: Damjanovic, S., Arnaldi, R., Averbeck, R., Banicz, K., Castor, J., Chaurand, B., Cicalo, C., Colla, A., Cortese, P., David, A., De Falco, A., Devaux, A., Drees, A., Ducroux, L., Enyo, H., Ferretti, A., Floris, M., Forster, A., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Lourenco, C., Lozano, J., Manso, F., Masoni, A., Martins, P., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, Philippe, Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H.J., Tieulent, R., Usai, G., Veenhof, R., Wohri, H.K., 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), Peter Jacobs and Xin-Nian Wang, 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), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Muon, Large Hadron Collider, Meson, Physics::Instrumentation and Detectors, 010308 nuclear & particles physics, Nuclear Theory, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, Yield (chemistry), 0103 physical sciences, Quark–gluon plasma, Mass spectrum, Nuclear Physics - Experiment, High Energy Physics::Experiment, Spectral function, Nuclear Experiment (nucl-ex), 010306 general physics, Low Mass, Nuclear Experiment
Abstract: The NA60 experiment at the CERN SPS has studied low-mass muon pairs in 158 AGeV In-In collisions. A strong excess of pairs is observed above the yield expected from neutral meson decays. After subtraction of the decay sources, the shape of the resulting mass spectrum is largely consistent with a dominant contribution from pi+pi- -> rho -> mu+mu- annihilation. The associated rho spectral function exhibits considerable broadening, but essentially no shift in mass. The acceptance-corrected pT spectra have a shape atypical for radial flow. They also significantly depend on mass, pointing to different sources in different mass regions. Both mass and pT spectra are compared to recent theoretical predictions., Prepared for International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2006), Asilomar, Pacific Grove, California, 9-16 Jun 2006
Published: 2007

21. J/$\psi$ suppression in In-In collisions at 158 GeV/nucleon

Author: Arnaldi, R., Arnaldi, NA60 Collaboration R., Averbeck, R., Banicz, K., Castor, J., Chaurand, B., Cicalo', C., Colla, A., Cortese, P., Damjanovic, S., David, A., DeFalco, A., Devaux, A., Drees, A., Ducroux, L., En'yo, H., Ferretti, A., Floris, M., Forster, A., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Lourenco, C., Lozano, J., Manso, F., Masoni, A., Martins, P., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H. J., Tieulent, R., Usai, G., Veenhof, R., Wohri, H. K., 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), 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), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: High Energy Physics::Experiment, Nuclear Physics - Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract: The NA60 experiment has studied J/$\psi$ production in Indium-Indium collisions at 158 A$\cdot$GeV. In this paper we present an updated set of results obtained with the complete set of available statistics and an improved alignment of the vertex tracker. The centrality dependence of the J/$\psi$ production, obtained with an analysis technique based only on the J/$\psi$ sample, indicates that a suppression beyond that induced by nuclear absorption is present in In-In collisions, setting in at $\sim$80 participant nucleons. A first study of the systematic errors related with this measurement is discussed. We also present preliminary results on the J/$\psi$ azimuthal distributions., Comment: 8 pages, 3 figures, proceedings of Hard Probes 2006 International Conference
Published: 2006

22. $\psi^{\prime}$ production in Pb-Pb collisions at 158 GeV/nucleon

Author: Alessandro, B., Alexa, C., Arnaldi, R., Atayan, M., Beolè, S., Boldea, V., Bordalo, P., Borges, G., Castor, J., Chaurand, B., Cheynis, B., Chiavassa, E., Cicalò, C., Comets, M.P., Constantinescu, S., Cortese, P., Falco, A.De, Marco, N.De, Dellacasa, G., Devaux, A., Dita, S., Drapier, O., Fargeix, J., Force, P., Gallio, M., Gerschel, C., Giubellino, P., Golubeva, M.B., Gonin, M., Grigoryan, A., Grossiord, J.Y., Guber, F.F., Guichard, A., Gulkanyan, H., Idzik, M., Jouan, D., Karavicheva, T.L., Kluberg, L., Kurepin, A.B., Bornec, Y.Le, Lourenço, C., Cormick, M.Mac, Marzari-Chiesa, A., Masera, M., Masoni, A., Monteno, M., Musso, A., Petiau, P., Piccotti, A., Pizzi, J.R., Prino, F., Puddu, G., Quintans, C., Ramello, L., Ramos, S., Riccati, L., Romana, A., Santos, H., Saturnini, P., Scomparin, E., Serci, S., Shahoyan, R., Sitta, M., Sonderegger, P., Tarrago, X., Topilskaya, N.S., Usai, G.L., Vercellin, E., Villatte, L., and Willis, N.
Subjects: High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment
Abstract: $\psi{prime}$ production is studied in Pb-Pb collisions at 158 GeV/c per nucleon incident momentum. Absolute cross-sections are measured and production rates are investigated as a function of the centrality of the collision. The results are compared with those obtained for lighter colliding systems and also for the $J/\psi$ meson produced under identical conditions. psi' production is studied in Pb-Pb collisions at 158 GeV/c per nucleon incident momentum. Absolute cross-sections are measured and production rates are investigated as a function of the centrality of the collision. The results are compared with those obtained for lighter colliding systems and also for the J/psi meson produced under identical conditions.
Published: 2006

23. Low mass dimuon production in proton-nucleus and indium-indium collisions

Author: Wöhri, H.K., Arnaldi, R., Averbeck, R., Banicz, K., Castor, J., Chaurand, B., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., David, A., De Falco, A., Devaux, A., Drees, A., Ducroux, L., En'Yo, H., Ferretti, A., Floris, M., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Kneil, M., Kluberg, L., Lourenço, C., Lozano, J., Manso, F., Masoni, A., Martins, P., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, Philippe, Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Shahoyan, R., Scomparin, E., Seixas, J., Serci, S., Sonderegger, P., Specht, H.J., Tieulent, R., Usai, G., Veenhof, R., 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), 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 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), NA60, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), 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)
Subjects: Physics::Instrumentation and Detectors, Nuclear Theory, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Physics - Experiment, High Energy Physics::Experiment, Nuclear Experiment
Abstract: NA60; International audience; The NA60 experiment studied low-mass dimuon production in proton-nucleus and indium-indium collisions at the CERN SPS. While the p-A data can be well described by a superposition of light neutral meson decays, an excess is observed in the heavy-ion data, increasing with collision centrality, with respect to these expected sources. Thanks to the high statistics and good quality of our measurement, we can subtract the muon pairs due to h, h0, w and f decays from the signal dimuon mass distribution. The resulting spectra are compatible with a r spectral function broadening from peripheral to central collisions, with no change in the pole mass.
Published: 2005

24. J/$\psi$ suppression in indium-indium collisions at SPS energies

Author: Lourenço, C., Averbeck, R., Banicz, K., Castor, J., Chaurand, B., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., David, A., De Falco, A., Devaux, A., Drees, A., Ducroux, L., En'Yo, H., Ferretto, A., Floris, M., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Kneil, M., Kluberg, L., Lozano, J., Manso, F., Masoni, A., Martins, P., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, Philippe, Puddu, G., Radermacher, E., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shaoyan, R., Sonderegger, P., Specht, H.J., Tieulent, R., Usai, G., Veenhof, R., Wöhri, H.K., 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), 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), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: Nuclear Theory, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, Nuclear Experiment
Abstract: NA60; International audience; In 2003, NA60 collected data on dimuon production in indium-indium collisions at 158 GeV per incident nucleon, to study several anomalies previously observed in high-energy heavy-ion collisions at the CERN SPS. Among these anomalies stands the observation, by NA50, that the production yield of J/y mesons is suppressed in central Pb-Pb collisions beyond the normal nuclear absorption defined by proton-nucleus data. This behaviour was predicted to occur if the matter produced in these extreme collisions goes through a phase of deconfined partonic matter, where the charmonium states would be dissolved either due to the screening of their binding potential when the medium temperature exceeds certain critical thresholds (thermal transition, QGP) or when the density of interacting partons exceeds certain thresholds (geometrical transition, percolation). Thanks to its exceptionally good vertexing capabilities, NA60 is able to accurately study the centrality dependence of J/y production without using the Drell-Yan sample as reference. Our data shows that the J/y is anomalously suppressed for In-In collisions with more than ~ 90 participants nucleons. The comparison with three theoretical predictions shows that none of them properly describes the observed suppression pattern.
Published: 2005

25. Study of dimuon production in Indium-Indium collisions with the NA60 experiment

Author: Shahoyan, R., Arnaldi, R., Banicz, K., Castor, J., Chaurand, B., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., David, Andre, Falco, A., Devaux, A., Ducroux, L., En Yo, H., Ferretti, A., Floris, M., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Lozano, J., Lourenco, C., Manso, F., Masoni, A., Martins, P., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Enrico Scomparin, Seixas, J., Serci, S., Sonderegger, P., Specht, H. J., Tieulent, R., Usai, G., Veenhof, R., Woehri, H. K., 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), NA60, Université Claude Bernard Lyon 1 (UCBL), 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)
Subjects: High Energy Physics - Experiment (hep-ex), Physics::Instrumentation and Detectors, High Energy Physics::Phenomenology, Nuclear Theory, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment, High Energy Physics - Experiment
Abstract: The NA60 experiment at the CERN-SPS is devoted to the study of dimuon production in heavy-ion and proton-nucleus collisions. We present preliminary results from the analysis of Indium-Indium collisions at 158 GeV per nucleon. The topics covered are low mass vector meson production, J/psi production and suppression, and the feasibility of the open charm measurement from the dimuon continuum in the mass range below the J/psi peak., Contribution at XXXXth Rencontres de Moriond, "QCD and High Energy Hadronic Interactions"
Published: 2005

26. NA60 low mass di-muon data

Author: Veenhof, R., Arnaldi, R., Banicz, K., Castor, J., Chaurand, B., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., David, A., De Falco, A., Devaux, A., Ducroux, L., En'Yo, H., Ferretti, A., Floris, M., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Lozano, J., Lourenço, C., Manso, F., Masoni, A., Martins, P., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, Philippe, Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H.J., Tieulent, R., Usai, G., Wöhri, H.K., 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), 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 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), NA60, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), 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)
Subjects: Nuclear Theory, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, Nuclear Experiment
Abstract: NA60; Data taken by NA60 in 2002 with a 400 GeV proton beam on various nuclear targets confirms that dimuon production with a mass below the $\phi$ can be explained by meson decays. The production cross sections of these mesons agree with what earlier experiments have reported. In 2003, NA60 has recorded a large sample of interactions between a 158 GeV/n In beam and In targets. Pending a study of the background, we do not comment on the existence of an excess in this data sample, but our measurements shed new light on the apparent conflict between NA49 and NA50 measurements of the inverse transverse mass slope of $\phi$ production. The NA60 measurement of the $\phi/(\rho + \omega)$ ratio as function of number of participants agrees well with earlier measurements, both in proton and ion data.
Published: 2005

27. Measuring displaced muon pairs in Indium-Indium collisions at the CERN SPS

Author: David, A., Arnaldi, R., Banicz, K., Castor, J., Chaurand, B., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., De Falco, A., Devaux, A., Ducroux, L., En'Yo, H., Ferretti, A., Floris, M., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Lozano, J., Lourenço, C., Manso, F., Masoni, A., Martins, P., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, Philippe, Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H.J., Tieulent, R., Usai, G., Veenhof, R., Wöhri, H.K., 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), 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 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), NA60, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), 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)
Subjects: Physics::Instrumentation and Detectors, Nuclear Theory, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, Nuclear Experiment
Abstract: NA60; The NA60 experiment at the CERN-SPS studies dimuon production in proton-nucleus and heavy-ion collisions. We report on the effort towards measuring open charm in Indium-Indium collisions. Altough work on the final background subtraction procedure is still under way, we can already demonstrate that the detector performance is adequate to separate prompt dimuons from muon pairs originating in distant D$\bar{D}$ decays.
Published: 2005

28. The production of $\rho$, $\omega$ and$ \phi$ vector-mesons by protons and sulphur ions with incident momentum of 200 GeV/c per nucleon

Author: Abreu, M.C., Astruc, J., Baglin, C., Baldit, A., Bedjidian, M., Bordalo, P., Borges, G., Bussière, A., Castor, J., Chaurand, B., Chevrot, I., Cheynis, B., Devaux, A., Drapier, O., Espagnon, B., Fargeix, J., Ferreira, R., Force, P., Gerschel, C., Grossiord, J.-Y., Guichard, A., Guimaraes, J., Haroutunian, R., Jouan, D., Kluberg, L., Lourenço, C., Mourgues, S., Petiau, P., Pizzi, J.-R., Quintans, C., Ramos, S., Romana, A., Santos, H., Saturnini, P., Shahoyan, R., Sonderegger, P., Tarrago, X., 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), 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), 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), NA38, 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), 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), 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: [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment
Abstract: NA38 EI; The production of $\rho$ , $\omega$ and $\phi$ vector-mesons, detected through their $\mu\mu$ decay channel, is studied in p-W, S-S, S-Cu and S-U reactions at 200 GeV/c per nucleon incident momentum. Their inclusive cross-sections are determined in various transverse momentum intervals and their dependence on the projectile and target mass numbers is investigated. The relative yield $B_{\mu\mu}\sigma_{\phi}/(B_{\mu\mu}\sigma_{\rho} + B_{\mu\mu}\sigma_{\omega})$ is measured, both as a function of the transverse momentum, pT, and of the collision centrality. While this ratio exhibits no significant dependence with pT, it clearly increases with the centrality of the collision. Effective temperatures deduced from the transverse mass spectra, $d\sigma/dM_T$ , lead to values of $T_{\rho + \omega}$ equal or slightly higher than $T_{\phi}$ . Both these effective temperatures smoothly increase from p-W to S-U reactions.
Published: 2005

29. Low mass dimuon production in proton-nucleus collisions with the NA60 apparatus

Author: Wohri, Kw, Arnaldi, R, Averbeck, R, Banicz, K, Buytaert, J, Castor, J, Chaurand, B, Cheynis, B, Cicalo, C, Cortese, P, David, A, de Falco, A, Devaux, A, Drees, A, Ducroux, L, En'Yo, H, Ferretti, Alessandro, Floris, M, Force, P, Grossiord, Jy, Guettet, N, Guichard, A, Gulkanian, H, Heuser, J, Keil, M, Kluberg, L, Lozano, J, Lourenzo, C, Manso, F, Masoni, A, Neves, A, Ohnishi, H, Oppedisano, C, Puddu, G, Radermacher, E, Rosinsky, P, Scomparin, E, Seixas, J, Serci, S, Shahoyan, R, Sonderegger, P, Usai, G., 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), 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, Particle physics, Range (particle radiation), Physics and Astronomy (miscellaneous), Proton, Meson, 010308 nuclear & particles physics, Nuclear Theory, chemistry.chemical_element, 01 natural sciences, 7. Clean energy, Omega, Nuclear physics, chemistry, 0103 physical sciences, Mass spectrum, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Production (computer science), High Energy Physics::Experiment, Beryllium, 010306 general physics, Low Mass, Nuclear Experiment, Engineering (miscellaneous)
Abstract: During the June 2002 run NA60 collected around 600 000 dimuon triggers in proton-nucleus collisions at 400 GeV. We show that the collected dimuon mass spectra can be understood in terms of known sources. The specific target setup, consisting of Beryllium, Indium and Lead targets, simultaneously exposed to the beam, allowed us to study the nuclear dependence of the production cross-section of the $\omega$ and $\phi$ resonances. The elementary nucleon-nucleon production cross-sections at 400 GeV for the $\rho$, $\omega$ and $\phi$ mesons are also presented. By using the $\eta$-Dalitz decay, dominating the mass range below 450 MeV, we, furthermore, extracted the $\eta$ production cross-section and its nuclear dependence. The results are discussed in the framework of previous measurements, mostly obtained in different decay channels, performed by NA27, HELIOS-1 and CERES-TAPS.
Published: 2004

30. J/$\psi$ production in Indium-Indium collisions

Author: Arnaldi, R., Averbeck, R., Banicz, K., Castor, J., Chaurand, B., Cicalo', C., Colla, A., Cortese, P., Damjanovic, S., David, A., DE FALCO, A., Devaux, A., Drees, A., Ducroux, L., En'Yo, H., Fargeix, J., Ferretti, Alessandro, Floris, M., Foerster, A., Force, P., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J. M., Keil, M., Kluberg, L., Loureno, C., Lozano, J., Manso, F., Masoni, A., Martins, P., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, P. H., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Specht, H. J., Tieulent, R., Usai, G., Veenhof, R., Woehri, H. K., 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), 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 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), NA60, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), 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)
Subjects: Physics, Particle physics, Large Hadron Collider, Physics and Astronomy (miscellaneous), 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, chemistry.chemical_element, Elementary particle, Radiation, Polarization (waves), 01 natural sciences, 7. Clean energy, Nuclear physics, chemistry, 0103 physical sciences, Transverse momentum, Quark–gluon plasma, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, Quantum field theory, 010306 general physics, Nuclear Experiment, Engineering (miscellaneous), Indium
Abstract: The study of dilepton production in heavy-ion collisions at the CERN SPS provided some of the most interesting observations done so far in the search for the quark gluon plasma. However, several aspects of the understanding of these measurements need to be clarified. For example, the study of the J/$\psi$ production in different colliding systems should help to disentangle which is the variable driving the J/$\psi$ suppression. The NA60 experiment, with a new radiation tolerant Silicon pixel detector, studied Indium-Indium interactions in the year 2003. In this paper, we present the J/$\psi$ / DY ratio, integrated over all the centralities of the collisions, together with a first study of the J/$\psi$ transverse momentum and polarization.
Published: 2004

31. The J/$\psi$ normal nuclear absorption

Author: Alessandro, B., Alexa, C., Arnaldi, R., Atayan, M., Beolè, S., Boldea, V., Bordalo, P., Castanier, C., Castor, J., Chaurand, B., Cheynis, B., Chiavassa, E., Cicalo, C., Comets, M.-P., Constantinescu, S., Cortese, P., De Falco, A., De Marco, N., Dellacasa, G., Devaux, A., Dita, S., Fargeix, J., Force, P., Gallio, M., Gerschel, C., Giubellino, P., Golubeva, M.B., Grigorian, A.A., Grigoryan, S., Guber, F.F., Guichard, A., Gulkanyan, H., Idzik, M., Jouan, D., Karavicheva, T.L., Kluberg, L., Kurepin, A.B., Le Bornec, Y., Lourenço, C., Mac Cormick, M., Mazari-Chiesa, A., Masera, M., Masoni, A., Monteno, M., Musso, A., Petiau, P., Piccotti, A., Pizzi, J.-R., Prino, F., Puddu, G., Quintans, C., Ramello, L., Ramos, S., Riccati, L., Santos, H., Saturnini, P., Scomparin, E., Serci, S., Shahoyan, R., Sigaudo, F., Sitta, M., Sonderegger, P., Tarrago, X., Topilskaya, N.S., Usai, G.L., Vercellin, E., Villatte, L., Willis, N., Wu, T., Borges, G., 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), 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 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), 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), NA50, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-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), and 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)
Subjects: Physics, Physics and Astronomy (miscellaneous), 010308 nuclear & particles physics, Nuclear Theory, Analytical chemistry, Elementary particle, Nuclear matter, 01 natural sciences, Nuclear physics, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Absorption (logic), 010306 general physics, Nuclear Experiment, Engineering (miscellaneous)
Abstract: We present a new determination of the ratio of cross-sections $({\rm J}/\psi)/{\rm DY}$ as expected for nucleus-nucleus reactions if ${\rm J}/\psi$ would only be normally absorbed by nuclear matter. This anticipated behaviour is based on proton-nucleus data exclusively, and compared, as a function of centrality, with updated S-U results from experiment NA38 and with the most recent Pb-Pb results from experiment NA50.
Published: 2004

32. A first look at open charm production Indium-Indium collisions at SPS energies

Author: Shahoyan, R, Arnaldi, R, Averbeck, R, Banicz, K, Castor, J, Chaurand, B, Cicalo, C, Colla, A, Cortese, P, Damjanovic, S, David, A, DE FALCO, A, Devaux, A, Drees, A, Ducroux, L, En'Yo, H, Ferretti, Alessandro, Floris, M, Force, P, Guettet, N, Guichard, A, Gulkanian, H, Heuser, J, Keil, M, Kluberg, L, Lozano, J, Laurenco, C, Manso, F, Masoni, A, Martins, P, Neves, A, Ohnishi, H, Oppedisano, C, Parracho, P, Pillot, P, Puddu, G, Radermacher, E, Ramalhete, P, Rosinsky, P, Scomparin, E, Seixas, J, Serci, S, Sonderegger, P, Specht, Hj, Tieulent, R, Usai, G, Veenhof, R, Wohri, Hk, 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), C. Lourenço, Helmut Satz, 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), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: Physics, Particle physics, Background subtraction, Meson production, Muon, Physics and Astronomy (miscellaneous), 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, Nuclear Theory, chemistry.chemical_element, 7. Clean energy, 01 natural sciences, Nuclear physics, chemistry, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, Vector meson, Open charm, 010306 general physics, Low Mass, Nuclear Experiment, Engineering (miscellaneous), Indium
Abstract: NA60 is an experiment at the CERN-SPS devoted to the study of dimuon production in heavy-ion and proton-nucleus collisions. The main topics under study are low mass vector meson production, J/$\psi$ production and suppression, and the sources of the dimuon continuum in the mass range 1.2-2.7 GeV/c2. In 2003, NA60 collected $\sim 230$ million dimuon events from Indium-Indium collisions. We present preliminary results of the analysis of this data sample in view of measuring the open charm contribution to the dimuon spectrum. Although we are still working on the final background subtraction procedure, we can already demonstrate that the detector performance is good enough to allow the separation of prompt dimuons from muon pairs originating in distant D $\overline{\rm D}$ decays.
Published: 2004

33. J/$\psi$ production in indium–indium collisions

Author: Ohnishi, H., Arnaldi, R., Averbeck, R., Banicz, K., Borer, K., Buytaert, J., Castor, J., Chaurand, B., Chen, W., Cheynis, B., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., David, A., De Falco, A., De Marco, N., Devaux, A., Drees, A., Ducroux, L., En'Yo, H., Ferretti, A., Floris, M., Förster, A., Force, P., Grigorian, A., Grossiord, J.-Y., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Li, Zhenyu, Lourenço, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Oppedisano, C., Parracho, P., Pillot, Philippe, Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., J Specht, H., Tieulent, R., Tveiten, E., Usai, G., Vardanyan, H., Veenhof, R., Wöhri, H., 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), 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 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, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-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), 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: Nuclear reaction, Physics, Nuclear and High Energy Physics, Large Hadron Collider, Meson, Proton, 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, High Energy Physics::Phenomenology, Nuclear Theory, Quarkonium, 01 natural sciences, Particle identification, Nuclear physics, Strange matter, 0103 physical sciences, Quark–gluon plasma, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, 010306 general physics, Nuclear Experiment
Abstract: NA60; Dilepton measurements are one of the most powerful tools for investigating the quark–gluon plasma formation in high-energy heavy-ion collisions. The NA60 experiment, taking place at the CERN SPS, studies the production of prompt dimuons and open charm in collisions induced by proton and heavy-ion beams on nuclear targets. In this paper, some preliminary results from the indium–indium dataset are presented.
Published: 2004

34. First results from NA60 on low mass muon pair production in In-In collisions at 158 GeV/nucleon

Author: Damjanovic, S., Arnaldi, R., Averbeck, R., Banicz, K., Borer, K., Buytaert, J., Castor, J., Chaurand, B., Chen, W., Cheynis, B., Cicalo, C., Colla, A., Cortese, P., David, A., De Falco, A., De Marco, N., Devaux, A., Drees, A., Ducroux, L., En'Yo, H., Ferretti, A., Floris, M., Förster, A., Force, P., Grigorian, A., Grossiord, J.-Y., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Li, Zhenyu, Lourenço, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, Philippe, Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., J Specht, H., Tieulent, R., Tveiten, E., Usai, G., Vardanyan, H., Veenhof, R., Wöhri, H., 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), 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 and High Energy Physics, Muon, Large Hadron Collider, Meson, Physics::Instrumentation and Detectors, Nuclear Theory, Inverse, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 7. Clean energy, Nuclear physics, Pair production, Nuclear Physics - Experiment, Production (computer science), High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nucleon, Low Mass, Nuclear Experiment
Abstract: The NA60 experiment at the CERN SPS studies dimuon production in proton-nucleus and nucleus-nucleus collisions. The combined information from a novel vertex telescope made of radiation-tolerant silicon pixel detectors and from the muon spectrometer previously used in NA50 allows for a precise measurement of the muon vertex and a much improved dimuon mass resolution. We report on first results from the data taken for Indium-Indium collisions at 158 AGeV/nucleon in 2003, concentrating on a subsample of about 370 000 muon pairs in the mass range $, Comment: 9 pages, 6 figures. Plenary talk, SQM2004 conference, Cape Town, South Africa 15-20 September, 2004. To be published in Journal of Physics G: Nuclear and Particle Physics
Published: 2004

35. Study of the J/$\psi$ production and suppression in In–In collisions at the CERN SPS

Author: Colla, A., Arnaldi, R., Averbeck, R., Banicz, K., Borer, K., Buytaert, J., Castor, J., Chaurand, B., Chen, W., Cheynis, B., Cicalo, C., Cortese, P., Damjanovic, S., David, A., De Falco, A., De Marco, N., Devaux, A., Drees, A., Ducroux, L., En'Yo, H., Ferretti, A., Floris, M., Förster, A., Force, P., Grigorian, A., Grossiord, J.-Y., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Li, Zhenyu, Lourenço, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Pillot, Philippe, Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., J Specht, H., Tieulent, R., Tveiten, E., Usai, G., Vardanyan, H., Veenhof, R., Wöhri, H., 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), 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 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, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-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), 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, Large Hadron Collider, Muon, Plasma formation, Meson, Proton, 010308 nuclear & particles physics, Nuclear Theory, 01 natural sciences, Preliminary analysis, Nuclear physics, 0103 physical sciences, Quark–gluon plasma, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, 010306 general physics, Nucleon, Nuclear Experiment
Abstract: NA60; The NA60 experiment aims at measuring the kinematics of the muon pairs produced in ultra-relativistic nuclear collisions. The use of dileptonic probes in the search for quark–gluon plasma formation has been carried on by several experiments at the CERN SPS, which have provided some of the most interesting observations; nevertheless certain important questions remain open. One of them is the interpretation of the anomalous suppression of the J/$\psi$ meson in Pb–Pb collisions with respect to the yields extrapolated from the proton–nucleus data taken by the NA50 experiment. The NA60 experiment has recently taken data on J/$\psi$ production in indium–indium collisions: the comparison of the suppression patterns in the two systems (In–In with respect to Pb–Pb) should help in understanding which is the physical variable driving the J/$\psi$ suppression. In this paper, after briefly summarizing the NA60 physics motivation and detector concept, we present the first results from In–In collisions at 158 GeV/nucleon, focusing on the preliminary analysis of charmonia production and suppression.
Published: 2004

36. $\psi'$ production in nucleus–nucleus collisions at CERN SPS

Author: Santos, H., Alessandro, B., Alexa, C., Arnaldi, R., Atayan, M., Beole, S., Boldea, V., Bordalo, P., Borges, C., Castanier, C., Castor, J., Chaurand, B., Cheynis, B., Chiavassa, E., Cicalo, C., Comets, M.P., Constantinescu, S., Cortese, P., De Falco, A., De Marco, N., Dellacasa, G., Devaux, A., Dita, S., Fargeix, J., Force, P., Gallio, M., Gerschel, C., Giubellino, P., Golubeva, M.B., Grigorian, A.A., Grigoryan, S., Guber, F.F., Guichard, A., Gulkanyan, H., Idzik, M., Jouan, D., Karavitcheva, T.L., Kluberg, L., Kurepin, A.B., Le Bornec, Y., Lourenço, C., Mac Cormick, M., Marzari-Chiesa, A., Masera, M., Masoni, A., Monteno, M., Musso, A., Petiau, P., Picotti, A., Pizzi, J.-R., Prino, F., Puddu, G., Quintans, C., Ramello, L., Ramos, S., Riccati, L., Saturnini, P., Scomparin, P., Serci, S., Shahoyan, R., Sigaudo, F., Sitta, M., Sonderegger, P., Tarrago, X., Topilskaya, N.S., Usai, G.L., Vercellin, E., Villatte, L., Willis, N., Wu, T., 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), 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 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), 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), NA50, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-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), and 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)
Subjects: Physics, Nuclear and High Energy Physics, Particle physics, Large Hadron Collider, Proton, 010308 nuclear & particles physics, Nuclear Theory, 7. Clean energy, 01 natural sciences, Momentum, Nuclear physics, medicine.anatomical_structure, 0103 physical sciences, medicine, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, Nucleon, Nuclear Experiment, 010303 astronomy & astrophysics, Nucleus, Production rate
Abstract: NA50 EI; We report results on $\psi'$ production in Pb–Pb interactions at 158 GeV/c per nucleon incident momentum, from data collected by the NA50 experiment at CERN SPS. A comparison of proton- and sulfur-induced collisions shows a similar $\psi'$ production rate per nucleon–nucleon collision for S–U and Pb–Pb reactions, decreasing with increasing centrality and significantly lower than the rate measured from proton-induced reactions. This feature contrasts with J/$\psi$ production which exhibits a similar behaviour for reactions induced by protons and by sulfur nuclei and a significantly suppressed rate for Pb–Pb interactions.
Published: 2004

37. Accurate measurements of dimuon production in the NA60 experiment

Author: Sonderegger, P., Arnaldi, R., Averbeck, R., Banicz, K., Borer, K., Buytaert, J., Castor, J., Chaurand, B., Chen, W., Cheynis, B., Cicalo, C., Colla, A., Cortese, P., Damjanovic, S., David, A., De Falco, A., De Marco, N., Devaux, A., Drees, A., Ducroux, L., En'Yo, H., Ferretti, A., Floris, M., Force, P., Grigorian, A., Grossiord, J.-Y., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Li, Zhenyu, Lourenço, C., Lozano, J., Manso, F., Martins, P., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Parracho, P., Puddu, G., Radermacher, E., Ramalhete, P., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shaholyan, R., Specht, H.J., Tieulent, R., Usai, G., Vardanyan, H., Veenhof, R., Wöhri, H., 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), 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 and High Energy Physics, Particle physics, Silicon pixel detectors, Muon, Nuclear collision, Proton, 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, Detector, Measure (physics), Tracking (particle physics), 01 natural sciences, Charged particle, Nuclear physics, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], High Energy Physics::Experiment, 010306 general physics, Nuclear Experiment
Abstract: NA60; Thanks to newly developed radiation-tolerant silicon pixel detectors, NA60 can measure dilepton production with unprecedented accuracy, by tracking the hundreads of charged particles produced in a high-energy nuclear collision and selecting those among them that match the two muons measured in the muon spectrometer. In this paper we briefly summarize the NA60 physics motivations, the detector concept, its implementation and some first results available from the data collected in 2002 and 2003, with proton and Indium beams.
Published: 2004

38. Dimuon production in p-nucleus and nucleus-nucleus collisions: the NA60 experiment

Author: Arnaldi, R., Usai, G., Banicz, K., Borer, K., Buytaert, J., Castor, J., Chaurand, B., Chen, W., Cheynis, B., Cicalo, C., Colla, A., Cortese, P., David, A., Devaux, A., Drees, A., Ducroux, L., Enyo, H., de Falco, A., Ferretti, A., Floris, M., Force, P., Grigorian, A., Grossiord, J.-Y., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Li, Zhenyu, Lourenco, C., Lozano, J., Manso, F., de Marco, N., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Puddu, G., Radermacher, E., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Vardanyan, H., Wohri, H., 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), 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 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, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-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), 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: Condensed Matter::Materials Science, High Energy Physics - Experiment (hep-ex), Physics::Instrumentation and Detectors, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment, Condensed Matter::Disordered Systems and Neural Networks, High Energy Physics - Experiment
Abstract: In this paper we present the preliminary results obtained by the NA60 experiment in Indium-Indium collisions at 158 GeV., Comment: 4 pages, 5 figures, to be published in the proceedings of the "XXXIXth Rencontres de Moriond", La Thuile, March 28th - April 4th, 2004
Published: 2004

39. Results on $\psi'$ production in nucleus-nucleus collisions at CERN-SPS

Author: Sitta, M., Alessandro, B., Alexa, C., Arnaldi, R., Atayan, M., Beole, S., Boldea, V., Bordalo, P., Borges, G., Castanier, C., Castor, J., Chaurand, B., Cheynis, B., Chiavassa, E., Cicalo, C., Comets, M.P., Constantinescu, S., Cortese, P., De Falco, A., De Marco, N., Dellacasa, G., Devaux, A., Dita, S., Fargeix, J., Force, P., Gallio, M., Gerschel, C., Giubellino, P., Golubeva, M.B., Grigorian, A.A., Grigoryan, S., Guber, F.F., Guichard, A., Gulkanyan, H., Idzik, M., Jouan, D., Karavitcheva, T.L., Kluberg, L., Kurepin, A.B., Le Bornec, Y., Lourenco, C., Mac Cormick, M., Marzari-Chiesa, A., Masera, M., Masoni, A., Monteno, M., Musso, A., Petiau, P., Piccotti, A., Pizzi, J.R., Prino, F., Puddu, G., Quintans, C., Ramello, L., Ramos, S., Riccati, L., Santos, H., Saturnini, P., Scomparin, E., Serci, S., Shahoyan, R., Sigaudo, F., Sonderegger, P., Tarrago, X., Topilskaya, N.S., Usai, G.L., Vercellin, E., Villatte, L., Willis, N., and Wu, T.
Subjects: Physics::Instrumentation and Detectors, Nuclear Theory, High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment
Abstract: We report results on $\psi'$ production as a function of centrality as measured by experiment NA50, at the CERN/SPS, in Pb-Pb collisions at an incident energy of 158 GeV per nucleon. We report results on $\psi'$ production as a function of centrality as measured by experiment NA50, at the CERN/SPS, in Pb-Pb collisions at an incident energy of 158 GeV per nucleon.
Published: 2004

40. Charmonia Suppression in Nucleus–Nucleus Interactions at CERN SPS

Author: Arnaldi, R., Alessandro, B., Alexa, C., Atayan, M., Baglin, C., Bedjidian, M., Beole, S., Boldea, V., Bordalo, P., Borenstein, S.R., Borges, C., Bussiere, A., Capelli, Laurent, Castanier, C., Castor, J., Chaurand, B., Cheynis, B., Chiavassa, E., Cicalo, C., Claudino, T., Comets, M.P., Constantinescu, S., Cortese, P., Cruz, J., De Falco, A., De Marco, N., Dellacasa, G., Devaux, A., Dita, S., Drapier, O., Espagnon, B., Fargeix, J., Force, P., Gallio, M., Gavrilov, Y.K., Gerschel, C., Giubellino, P., Golubeva, M.B., Gonin, M., Grigorian, A.A., Grigorian, S., Grossiord, J.-Y., Guber, F.F., Guichard, A., Gulkanyan, H., Hakobyan, R., Haroutunian, R., Idzik, M., Jouan, D., Karavitcheva, T.L., Kluberg, L., Kurepin, A.B., Le Bornec, Y., Lourenco, C., Macciotta, P., Mac Cormick, M., Marzari-Chiesa, A., Masera, M., Masoni, A., Monteno, M., Musso, A., Petiau, P., Picotti, A., Pizzi, J.-R., Prado Da Silva, W., Prino, F., Puddu, G., Quintans, C., Ramello, L., Ramos, S., Rato-Mendes, P., Riccati, L., Romana, A., Santos, H., Saturnini, P., Scalas, E., Scomparin, P., Serci, S., Shahoyan, R., Sigaudo, F., Sitta, M., Sonderegger, P., Tarrago, X., Topilskaya, N.S., Usai, G.L., Vercellin, E., Villatte, L., Willis, N., Wu, T., 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 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), 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, 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), 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 Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules)
Subjects: Nuclear and High Energy Physics, Phase transition, Particle physics, High Energy Physics::Lattice, Nuclear Theory, Hadron, General Physics and Astronomy, 7. Clean energy, 01 natural sciences, Nuclear physics, 0103 physical sciences, medicine, Nuclear Experiment, 010306 general physics, Physics, Large Hadron Collider, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Nuclear matter, medicine.anatomical_structure, Yield (chemistry), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Quark–gluon plasma, High Energy Physics::Experiment, Nucleon, Nucleus
Abstract: The NA50 experiment at CERN SPS has studied charmonium production in Pb−Pb collisions at 158 GeV/c per nucleon. According to the theoretical predictions the observation of the suppression of the J/ψ production yield is expected to be an unambiguous probe for a phase transition from ordinary nuclear matter towards a state in which quarks and gluons are deconfined.
Published: 2004

41. Charmonium production and nuclear absorption in p-A interactions at 450 GeV

Author: Alessandro, B, Alexa, C, Arnaldi, R, Atayan, M, Baglin, C, Baldit, A, Beolè, S, Boldea, V, Bordalo, P, Borenstein, S R, Borges, G, Bussière, A, Capelli, L, Castanier, C, Castor, J I, Chaurand, B, Cheynis, B, Chiavassa, E, Cicalò, C, Claudino, T, Comets, M P, Constans, N, Constantinescu, S, Cortese, P, Cruz, J, De Falco, A, De Marco, N, Dellacasa, G, Devaux, A, Dita, S, Drapier, O, Espagnon, B, Fargeix, J, Force, P, Gallio, M, Gerschel, C, Giubellino, P, Golubeva, M B, Gonin, M, Grigorian, A A, Grigorian, S, Grossiord, J Y, Guber, F F, Guichard, A, Gulkanian, H R, Idzik, M, Jouan, D, Karavitcheva, T L, Kluberg, L, Kurepin, A B, Le, Y, Le Bornec, Y, Lourenço, C, Macciotta, P, MacCormick, M, Marzari-Chiesa, A, Masera, M, Masoni, A, Monteno, M, Musso, A, Petiau, P, Piccotti, A, Pizzi, J R, Prino, F, Puddu, G, Quintans, C, Ramello, L, Ramos, S, Rato-Mendes, P, Riccati, L, Romana, A, Santos, H, Saturnini, P, Scomparin, E, Serci, S, Shahoyan, R, Sigaudo, F, Sitta, M, Sonderegger, P, Tarrago, X, Topilskaya, N S, Usai, G L, Vercellin, Ermanno, Villatte, L, Willis, N, 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 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, Particle physics, Large Hadron Collider, Physics and Astronomy (miscellaneous), 010308 nuclear & particles physics, Nuclear Theory, 01 natural sciences, Nuclear physics, medicine.anatomical_structure, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, medicine, Rapidity, High Energy Physics::Experiment, 010306 general physics, Absorption (electromagnetic radiation), Nuclear Experiment, Engineering (miscellaneous), Nucleus, Particle Physics - Experiment
Abstract: The production of J/$\psi$ and $\psi^{\prime}$ charmonium states in proton-nucleus interactions has been investigated by the NA50 experiment, at the CERN SPS. High statistics data sets were collected with collisions induced by 450GeV protons incident on Be, Al, Cu, Ag and W targets. The J/$\psi$ and $\psi^{\prime}$ production cross-sections have been determined for each p-A system and their dependences on the nucleus size have been studied, leading to the so-called normal nuclear absorption. Comparing the two patterns we see that the nuclear absorption is stronger for the $\psi^{\prime}$ than for the J/$\psi$. Given the high statistics of the data samples, the $x\_{F}$ (or rapidity) differential cross-sections of the J/$\psi$ and $\psi^{\prime}$ states have also been studied, for each of the target nuclei.
Published: 2003

42. Recent results on anomalous J/$\psi$ suppression in Pb-Pb collisions at 158 AGeV/c

Author: Santos, Helena, Alessandro, B., Alexa, C., Arnaldi, R., Atayan, M., Baglin, C., Baldit, A., Bedjidian, M., Beole, S., Boldea, V., Bordalo, P., Borenstein, S.R., Borges, G., Bussiere, A., Capelli, L., Castanier, C., Castor, J., Chaurand, B., Cheynis, B., Chiavassa, E., Cicalo, C., Claudino, T., Comets, M.P., Constantinescu, S., Cortese, P., Cruz, J., De Falco, A., De Marco, N., Dellacasa, G., Devaux, A., Dita, S., Drapier, O., Espagnon, B., Fargeix, J., Force, P., Gallio, M., Gavrilov, Y.K., Gerschel, C., Giubellino, P., Golubeva, M.B., Gonin, M., Grigorian, A.A., Grigorian, S., Grossiord, J.Y., Guber, F.F., Guichard, A., Gulkanyan, H., Hakobyan, R., Haroutunian, R., Idzik, M., Jouan, D., Karavitcheva, T.L., Kluberg, L., Kurepin, A.B., Le Bornec, Y., Lourenco, C., Macciotta, P., Cormick, M.Mac, Marzari-Chiesa, A., Masera, M., Masoni, A., Monteno, M., Musso, A., Petiau, P., Piccotti, A., Pizzi, J.R., Prado da Silva, W.L., Prino, F., Puddu, G., Quintans, C., Ramello, L., Ramos, S., Rato Mendes, P., Riccati, L., Romana, A., Saturnini, P., Scalas, E., Scomparin, E., Serci, S., Shahoyan, R., Sigaudo, F., Sitta, M., Sonderegger, P., Tarrago, X., Topilskaya, N.S., Usai, G.L., Vercellin, E., Villatte, L., Willis, N., Wu, T., 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), Augé E., Tran Thanh Van J., NA50, Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), 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), 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 Robert, Suzanne
Subjects: [PHYS.HPHE] Physics [physics]/High Energy Physics - Phenomenology [hep-ph], High Energy Physics - Experiment (hep-ex), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment, High Energy Physics - Experiment
Abstract: We report our latest results on charmonium suppression as measured at the CERN-SPS in Pb-Pb interactions at an incident beam momentum of 158 GeV/c per nucleon. Preliminary results obtained from the most recent sample of data collected in year 2000 under improved experimental conditions are compared with published results. For the most peripheral Pb-Pb collisions, J/psi suppression agrees with the normal absorption measured from interactions of lighter nuclei while a steady increasing abnormal supression is observed with increasing centrality., Comment: 4 pages, Latex, 6 Postscript figures, uses moriond.sty. To be submitted to XXXVIIIth Recontres de Moriond - QCD and Hadronic Interactions, Les Arcs, 22-29 March 2003
Published: 2003

43. The production of $\phi$, $\omega$ and $\rho$ mesons in p-, d-, S-. and Pb-induced reactions at the CERN SPS

Author: Jouan, D., Alessandro, B., Alexa, C., Arnaldi, R., Atayan, M., Baglin, C., Bedjidian, M., Beole, S., Boldea, V., Bordalo, P., Borenstein, S.R., Borges, C., Bussiere, A., Capelli, Laurent, Castanier, C., Castor, J., Chaurand, B., Cheynis, B., Chiavassa, E., Cicalo, C., Claudino, T., Comets, M.P., Constantinescu, S., Cortese, P., Cruz, J., De Falco, A., De Marco, N., Dellacasa, G., Devaux, A., Dita, S., Drapier, O., Espagnon, B., Fargeix, J., Force, P., Gallio, M., Gavrilov, Y.K., Gerschel, C., Giubellino, P., Golubeva, M.B., Gonin, M., Grigorian, A.A., Grigorian, S., Grossiord, J.-Y., Guber, F.F., Guichard, A., Gulkanyan, H., Hakobyan, R., Haroutunian, R., Idzik, M., Karavitcheva, T.L., Kluberg, L., Kurepin, A.B., Le Bornec, Y., Lourenco, C., Macciotta, P., Mac Cormick, M., Marzari-Chiesa, A., Masera, M., Masoni, A., Monteno, M., Musso, A., Petiau, P., Picotti, A., Pizzi, J.-R., Prado Da Silva, W., Prino, F., Puddu, G., Quintans, C., Ramello, L., Ramos, S., Rato-Mendes, P., Riccati, L., Romana, A., Santos, H., Saturnini, P., Scalas, E., Scomparin, P., Serci, S., Shahoyan, R., Sigaudo, F., Sitta, M., Sonderegger, P., Tarrago, X., Topilskaya, N.S., Usai, G.L., Vercellin, E., Villatte, L., Willis, N., Wu, T., 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), 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), 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), 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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), 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), 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 Theory, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment
Abstract: NA50 EI; 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 $\phi, \omega$ and $\rho$ 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

44. First results from the NA60 experiment at CERN

Author: Gianluca Usai, Arnaldi, R., Banicz, K., Borer, K., Buytaert, J., Castor, J., Chaurand, B., Chen, W., Cheynis, B., Cicalo, C., Colla, A., Cortese, P., David, Andre, Devaux, A., Drees, A., Ducroux, L., Enyo, H., Falco, A., Ferretti, A., Floris, M., Force, P., Grigorian, A., Grossiord, J. Y., Guettet, N., Guichard, A., Gulkanian, H., Heuser, J., Keil, M., Kluberg, L., Li, Z., Lourenco, C., Lozano, J., Manso, F., Marco, N., Masoni, A., Neves, A., Ohnishi, H., Oppedisano, C., Puddu, G., Radermacher, E., Rosinsky, P., Scomparin, E., Seixas, J., Serci, S., Shahoyan, R., Sonderegger, P., Vardanyan, H., Woehri, H. K., 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: High Energy Physics - Experiment (hep-ex), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Nuclear Theory, High Energy Physics::Phenomenology, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment, High Energy Physics - Experiment
Abstract: Since 1986, several heavy ion experiments have studied some signatures of the formation of the quark-gluon plasma and a few exciting results have been found. However, some important questions are still unanswered and require new measurements. The NA60 experiment, with a new detector concept that vastly improves dimuon detection in proton-nucleus and heavy-ion collisions, studies several of those open questions, including the production of open charm. This paper presents the experiment and some first results from data collected in 2002., Comment: Paper presented at the XXXVIII Rencontres de Moriond, QCD and High Energy Hadronic Interactions, Les Arcs, March 22-29, 2003. 4 pages, 6 figures
Published: 2003
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45. New results on nuclear dependence of J/$\psi$ and $\psi^{\prime}$ production in 450 GeV pA collisions

Author: Abreu, M.C., Alessandro, B., Alexa, C., Arnaldi, R., Atayan, M., Baglin, C., Baldit, A., Bedjidian, M., Beole, S., Boldea, V., Bordalo, P., Borenstein, S.R., Borges, G., Bussiere, A., Capelli, L., Castanier, C., Castor, J., Chaurand, B., Cheynis, B., Chiavassa, E., Cicalo, C., Claudino, T., Comets, M.P., Constans, N., Constantinescu, S., Cortese, P., Cruz, J., De Marco, N., De Falco, A., Dellacasa, G., Devaux, A., Dita, S., Drapier, O., Espagnon, B., Fargeix, J., Force, P., Gallio, M., Gavrilov, Y.K., Gerschel, C., Giubellino, P., Golubeva, M.B., Gonin, M., Grigorian, A.A., Grigorian, S., Grossiord, J.Y., Guber, F.F., Guichard, A., Gulkanyan, H., Hakobyan, R., Haroutunian, R., Idzik, M., Jouan, D., Karavitcheva, T.L., Kluberg, L., Kurepin, A.B., Le Bornec, Y., Lourenco, C., Macciotta, P., MacCormick, M., Marzari-Chiesa, A., Masera, M., Masoni, A., Monteno, M., Musso, A., Petiau, P., Piccotti, A., Pizzi, J.R., Prado da Silva, W., Prino, F., Puddu, G., Quintans, C., Ramos, S., Ramello, L., Rato Mendes, P., Riccati, L., Romana, A., Santos, H., Saturnini, P., Scalas, E., Scomparin, E., Serci, S., Shahoyan, R., Sigaudo, F., Silva, S., Sitta, M., Sonderegger, P., Tarrago, X., Topilskaya, N.S., Usai, G.L., Vercellin, E., Villatte, L., and Willis, N.
Subjects: Nuclear Theory, High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment
Abstract: To understand the reliability of the charmonia suppression as a signature of the Quark-Gluon Plasma formation in nucleus-nucleus collisions it is important first to understand the details of the production of J/$\psi$ and $\psi^{\prime}$ in pA interactions and the difference in the suppression of these two states. This report presents the results of the study by the NA50 collaboration of the J/$\psi$ and $\psi^{\prime}$ production in pA interactions at 450 GeV beam energy and its dependence on rapidity. It is shown that the $\psi^{\prime}$ suffers more suppression than the J/$\psi$, which is consistent with a similar observation made at 800 GeV beam energy by the E866/NuSea collaboration. To understand the reliability of the charmonia suppression as a signature of the Quark-Gluon Plasma formation in nucleus-nucleus collisions it is important first to understand the details of the production of J/psi and psi' in pA interactions and the difference in the suppression of these two states. This report presents the results of the study by the NA50 collaboration of the J/psi and psi' production in pA interactions at 450 GeV beam energy and its dependence on rapidity. It is shown that the psi' suffers more suppression than the J/psi, which is consistent with a similar observation made at 800 GeV beam energy by the E866/NuSea collaboration.
Published: 2002

46. Study of Muon Pairs and Vector Mesons Produced in High Energy Pb-Pb Interactions

Author: Ramos, S E, Karavicheva, T, Atayan, M, Bordalo, P, Constans, N P, Gulkanyan, H, and Kluberg, L
Subjects: Physics::Instrumentation and Detectors, Nuclear Theory, High Energy Physics::Experiment, Nuclear Experiment
Abstract: %NA50 %title\\ \\The experiment studies dimuons produced in Pb-Pb and p-A collisions, at nucleon-nucleon c.m. energies of $ \sqrt{s} $ = 18 and 30 GeV respectively. The setup accepts dimuons in a kinematical range roughly defined as $0.1$ < $y_{c.m.}$ < $1.0$ and $M_T$ > $1 GeV/c$, and stands maximal luminosity (5~10$^{7}$~Pb ions and 10$^7$ interactions per burst). The physics includes signals which probe QGP (Quark-Gluon Plasma), namely the $\phi$, J/$\psi$ and $\psi^\prime$ vector mesons and thermal dimuons, and reference signals, namely the (unseparated) $\rho$ and $\omega$ mesons, and Drell-Yan dimuons. The experiment is a continuation, with improved means, of NA38, and expands its study of {\it charmonium suppression} and {\it strangeness enhancement}.\\ \\The muons are measured in the former NA10 spectrometer, which is shielded from the hot target region by a beam stopper and absorber wall. The muons traverse 5~m of BeO and C. The impact parameter is determined by a Zero Degree Calorimeter (Ta with silica fibres). Energy dissipation and particle production are measured by an Electromagnetic Calorimeter (Pb and scintillating fibres) and a Multiplicity Detector (Si strips).\\ \\\\ \\ \\ \\
Published: 2002

47. The onset of the anomalous J/$\psi$ suppression in Pb-Pb collisions at the CERN SPS

Author: Arnaldi, R., Abreu, M.C., Alessandro, B., Alexa, C., Atayan, M., Baglin, C., Baldit, A., Bedjidian, M., Beole, S., Boldea, V., Bordalo, P., Borenstein, S.R., Borges, G., Bussiere, A., Capelli, L., Castor, J., Castanier, C., Chaurand, B., Cheynis, B., Chiavassa, E., Cicalo, C., Claudino, T., Comets, M.P., Constans, N., Constantinescu, S., Cortese, P., Cruz, J., De Marco, N., De Falco, A., Dellacasa, G., Devaux, A., Dita, S., Drapier, O., Espagnon, B., Fargeix, J., Force, P., Gallio, M., Gavrilov, Y.K., Gerschel, C., Giubellino, P., Golubeva, M.B., Gonin, M., Grigorian, A.A., Grigorian, S., Grossiord, J.Y., Guber, F.F., Guichard, A., Gulkanyan, H., Hakobyan, R., Haroutunian, R., Idzik, M., Jouan, D., Karavitcheva, T.L., Kluberg, L., Kurepin, A.B., Bornec, Y.Le, Lourenco, C., Macciotta, P., MacCormick, M., Marzari-Chiesa, A., Masera, M., Masoni, A., Monteno, M., Musso, A., Petiau, P., Piccotti, A., Pizzi, J.R., Prado da Silva, W., Prino, F., Puddu, G., Quintans, C., Ramos, S., Ramello, L., Rato Mendes, P., Riccati, L., Romana, A., Santos, H., Saturnini, P., Scalas, E., Scomparin, E., Serci, S., Shahoyan, R., Sigaudo, F., Silva, S., Sitta, M., Sonderegger, P., Tarrago, X., Topilskaya, N.S., Usai, G.L., Vercellin, E., Villatte, L., and Willis, N.
Subjects: Nuclear Theory, High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment
Abstract: The $J/\psi$ suppression observed by the NA50 experiment is one of the most striking signatures for quark gluon plasma formation in Pb-Pb collisions at 158 AGeV. The $J/\psi$ production has been studied as a function of the centrality of the collision estimated via the forward energy EZDC released in a zero degree calorimeter (ZDC). The study of the correlation between the number of participant nucleons in the collisions, Npart, and EZDC allows to check whether the $J/\psi$ suppression pattern vs. EZDC is compatible with a sudden $J/\psi$ suppression mechanism expressed as a function of Npart.
Published: 2001

48. $J/\psi$ suppression in Pb-Pb collisions at CERN SPS

Author: Prino, Francesco, Abreu, M.C., Alessandro, B., Alexa, C., Arnaldi, R., Ataian, M., Baglin, C., Baldit, A., Bedjidian, M., Beole, S., Boldea, V., Bordalo, P., Bussiere, A., Capelli, L., Casagrande, L., Castor, J., Chambon, T., Chaurand, B., Chevrot, I., Cheynis, B., Chiavassa, E., Cicalo, C., Claudino, T., Comets, M.P., Constans, N., Constantinescu, S., De Marco, N., De Falco, A., Dellacasa, G., Devaux, A., Dita, S., Drapier, O., Ducroux, L., Espagnon, B., Fargeix, J., Force, P., Gallio, M., Gavrilov, Y.K., Gerschel, C., Giubellino, P., Golubeva, M.B., Gonin, M., Grigorian, A.A., Grossiord, J.Y., Guber, F.F., Guichard, A., Gulkanian, H., Hakobian, R., Haroutunian, R., Idzik, M., Jouan, D., Karavitcheva, T.L., Kluberg, L., Kurepin, A.B., Le Bornec, Y., Lourenco, C., Macciotta, P., MacCormick, M., Marzari-Chiesa, A., Masera, M., Masoni, A., Mehrabian, S., Monteno, M., Musso, A., Petiau, P., Piccotti, A., Pizzi, J.R., Puddu, G., Quintans, C., Ramos, S., Ramello, L., Rato Mendes, P., Riccati, L., Romana, A., Ropotar, I., Saturnini, P., Scomparin, E., Serci, S., Shahoian, R., Silva, S., Sitta, M., Soave, C., Sonderegger, P., Tarrago, X., Topilskaya, N.S., Usai, G.L., Vercellin, E., Villatte, L., and Willis, N.
Subjects: High Energy Physics::Lattice, High Energy Physics::Phenomenology, Nuclear Theory, High Energy Physics::Experiment, Nuclear Experiment, Particle Physics - Experiment
Abstract: The NA38 and NA50 experiments at the CERN SPS have measured charmonium production in different colliding systems with the aim of observing a phase transition from ordinary hadronic matter towards a state in which quarks and gluons are deconfined (Quark Gluon Plasma, QGP). In fact it was predicted that the J/psi yield should be suppressed in deconfined matter. The analysis of the data collected by the NA50 experiment with Pb-Pb collisions at 158 GeV/c per nucleon shows that the J/psi is anomalously suppressed in central collisions and the observed pattern can be considered as a strong indication for QGP production. The NA38 and NA50 experiments at the CERN SPS have measured charmonium production in different colliding systems with the aim of observing a phase transition from ordinary hadronic matter towards a state in which quarks and gluons are deconfined (Quark Gluon Plasma, QGP). In fact it was predicted that the J/psi yield should be suppressed in deconfined matter. The analysis of the data collected by the NA50 experiment with Pb-Pb collisions at 158 GeV/c per nucleon shows that the J/psi is anomalously suppressed in central collisions and the observed pattern can be considered as a strong indication for QGP production.
Published: 2001

49. Experimental Status Of $J/\psi$ Suppression

Author: Kluberg, L, Abreu, M C, Alessandro, B, Alexa, C, Arnaldi, R, Astruc, J, Atayan, M, Baglin, C, Baldit, A, Bedjidian, M, Bellaiche, F, Beolè, S, Boldea, V, Bordalo, P, Bussière, A, Capelli,L, Capony, V, Casagrande, L, Castor, J, Chambon, T, Chaurand, B, Chevrot, I, Cheynis, B, Chiavassa, E, Cicalò, C, Comets, M P, Constans, N, Constantinescu, S, Cruz, J, De Falco, A, De Marco, N, Dellacasa, G, Devaux, A, Dita, S, Drapier, O, Ducroux, L, Espagnon, B, Fargeix, J, Filippov, S N, Fleuret, F, Force, P, Gallio, M, Gavrilov, Y K, Gerschel, C, Giubellino, P, Golubeva, M B, Gonin, M, Grigorian, A A, Grossiord, J Y, Guber, F F, Guichard, A, Gulkanyan, H, Hakobyan, R, Haroutunian, R, Idzik, M, Jouan, D, Karavitcheva, T L, Kurepin, A B, Le Bornec, Y, Lourenrço, C, Macciotta, P, Mac Cormick, M, Marzari- Chiesa, A, Masera, M, Masoni, A, Mehrabyan, S, Monteno, M, Mourgues, S, Musso, A, Ohlsson-Malek, F, Petiau, P, Piccotti, A, Pizzi, J R, Prado da Silva, W L, Puddu, G, Quintans, C, Racca, C, Ramello, L, Ramos, S, Rato-Mendes, P, Riccati, L, Romana, A, Ropotar, I, Saturnini, P, Scomparin, E, Serci, S, Shahoyan, R, Silva, S, Sitta, M, Soave, C, Sonderegger, P, Tarrago, X, Topilskaya, N S, Usai, G L, Vercellin, E, Villatte, L, and Willis, N
Subjects: Nuclear Theory, Nuclear Experiment, Particle Physics - Experiment
Abstract: The most recent results obtained by experiment NA50 show that the $J /\psi$ cross-section per nucleon-nucleon collision in semi-peripheral Pb-Pb reactions is "normally" suppressed in the sense that it follows the trend already observed from p-p and up to the most central S-U reactions. A clear change of behaviour is observed for more central Pb-Pb collisions which could be due to the transition of normal nuclear matter to its predicted Quark-Gluon Plasma state
Published: 2001

50. Low mass dimuon production in proton and ion induced interactions at SPS

Author: Abreu, M C., Alessandro, B., Alexa, C., Arnaldi, R., Astruc, J., Atayan, M., Baglin, C., Baldisseri, A., Baldit, A., Bedjidian, M., Bellaiche, F., Beole, S., Boldea, V., Bordalo, P., Bussiere, A., Capony, V., Casagrande, L., Castor, J., Chambon, T., Chaurand, B., Chevrot, I., Cheynis, B., Chiavassa, E., Cicalo, C., Comets, M P., Constans, N., Constantinescu, S., Contardo, D., De Falco, A., Dellacasa, G., De Marco, N., Descroix, E., Devaux, A., Dita, S., Drapier, O., Espagnon, B., Fargeix, J., Ferreira, R., Filippov, S N., Fleuret, F., Force, P., Gallio, M., Gavrilov, Y K., Gerschel, C., Giubellino, P., Golubeva, M B., Gonin, M., Gorodetzky, P., Grigorian, A A., Grossiord, J.-Y., Guber, F F., Guichard, A., Guillaud, J.P., Gulkanyan, H., Hakobyan, R., Haroutunian, R., Idzik, M., Jouan, D., Karavitcheva, T L., Kluberg, L., Kossakowski, R., Kurepin, A B., Le Bornec, Y., Liaud, P., Lourenco, C., Mac Cormick, M., Macciotta, P., Marzari-Chiesa, A., Masera, M., Masoni, A., Mehrabyan, S., Monteno, M., Mourgues, S., Musso, A., Ohlsson-Malek, F., Petiau, P., Piccotti, A., Pizzi, J.-R., Prino, F., Puddu, G., Quintans, C., Racca, C., Ramello, L., Ramos, S., Rato-Mendes, P., Riccati, L., Romana, A., Ronceux, B., Ropotar, I., Saturnini, P., Scomparin, E., Serci, S., Shahoyan, R., Silva, S., Sitta, M., Soave, C., Sonderegger, P., Staley, F., Tarrago, X., Topilskaya, N S., Usai, G L., Varela, J., Vercellin, E., Willis, N., 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), 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, Particle physics, Muon, Physics and Astronomy (miscellaneous), Proton, 010308 nuclear & particles physics, 01 natural sciences, Spectral line, Ion, Nuclear physics, Distribution (mathematics), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, Production (computer science), High Energy Physics::Experiment, 010306 general physics, Low Mass, Nuclear Experiment, Engineering (miscellaneous), Particle Physics - Experiment, Bar (unit)
Abstract: The low mass dimuon spectra collected in p-U collisions by the NA38 experiment significantly exceeds the total cross section expected from previous analysis, done by other experiments. The ‘excess’ events have a harder $p_{\mathrm{T}}$ distribution than the muon pairs from $\eta$ and $\omega$ Dalitz decays, expected to dominate the mass window 0.4–0.65 GeV/ $c^2$ . We conjecture that the excess events may be due to $q\bar{q}$ annihilations, negligible at low $p_{\mathrm{T}}$ but made visible by the $m_{\mathrm{T}}$ cut applied in the NA38 data. Taking this assumption to parametrise the p-U spectra, we proceed with the corresponding analysis of the S-Cu, S-U and Pb-Pb data, collected by the NA38 and NA50 experiments, comparing the measured low mass dimuon spectra with the ‘expected cocktail’.
Published: 2000

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