| Article | |
| Report number | arXiv:0812.3053 |
| Title | NA60 results on thermal dimuons |
| Author(s) |
Arnaldi, R. (Turin U. ; INFN, Turin) ; Banicz, K. (CERN ; Heidelberg U.) ; Borer, K. (Bern U., LHEP) ; Castor, J. (Clermont-Ferrand U.) ; Chaurand, B. (Ecole Polytechnique) ; Chen, W. (Brookhaven) ; Cicalo, C. (Cagliari U. ; INFN, Cagliari ; Turin U. ; INFN, Turin) ; Colla, A. (Cagliari U. ; INFN, Cagliari ; Turin U. ; INFN, Turin) ; Cortese, P. (Cagliari U. ; INFN, Cagliari ; Turin U. ; INFN, Turin) ; Damjanovic, S. (CERN) ; David, A. (CERN ; Lisbon, CFTP ; Lisbon, IST) ; Falco, A. (Cagliari U. ; INFN, Cagliari ; Clermont-Ferrand U.) ; Devaux, A. (Cagliari U. ; INFN, Cagliari ; Clermont-Ferrand U.) ; Ducroux, L. (Lyon, IPN) ; Enyo, H. (Nishina Ctr., RIKEN) ; Fargeix, J. (Clermont-Ferrand U.) ; Ferretti, A. (Turin U. ; INFN, Turin) ; Floris, M. (Cagliari U. ; INFN, Cagliari ; CERN) ; Forster, A. (Cagliari U. ; INFN, Cagliari ; CERN) ; Force, P. (Clermont-Ferrand U.) ; Guettet, N. (CERN ; Clermont-Ferrand U.) ; Guichard, A. (Lyon, IPN) ; Gulkanian, H. (Yerevan Phys. Inst.) ; Heuser, J.M. (Nishina Ctr., RIKEN) ; Keil, M. (CERN ; Lisbon, CFTP ; Lisbon, IST) ; Kluberg, L. (Ecole Polytechnique) ; Li, Z. (Brookhaven) ; Lourenco, C. (CERN) ; Lozano, J. (Lisbon, CFTP ; Lisbon, IST) ; Manso, F. (Clermont-Ferrand U.) ; Martins, P. (CERN ; Lisbon, CFTP ; Lisbon, IST) ; Masoni, A. (Cagliari U. ; INFN, Cagliari ; Lisbon, CFTP ; Lisbon, IST) ; Neves, A. (Cagliari U. ; INFN, Cagliari ; Lisbon, CFTP ; Lisbon, IST) ; Ohnishi, H. (Nishina Ctr., RIKEN) ; Oppedisano, C. (Turin U. ; INFN, Turin) ; Parracho, P. (CERN ; Lisbon, CFTP ; Lisbon, IST) ; Pillot, P. (Lyon, IPN) ; Poghosyan, T. (Yerevan Phys. Inst.) ; Puddu, G. (Cagliari U. ; INFN, Cagliari ; CERN) ; Radermacher, E. (Cagliari U. ; INFN, Cagliari ; CERN) ; Ramalhete, P. (CERN ; Lisbon, CFTP ; Lisbon, IST) ; Rosinsky, P. (CERN) ; Scomparin, E. (Turin U. ; INFN, Turin) ; Seixas, J. (Lisbon, CFTP ; Lisbon, IST) ; Serci, S. (Cagliari U. ; INFN, Cagliari ; CERN ; Lisbon, CFTP ; Lisbon, IST) ; Shahoyan, R. (Cagliari U. ; INFN, Cagliari ; CERN ; Lisbon, CFTP ; Lisbon, IST) ; Sonderegger, P. (Lisbon, CFTP ; Lisbon, IST) ; Specht, H.J. (Heidelberg U.) ; Tieulent, R. (Lyon, IPN) ; Usai, G. (Cagliari U. ; INFN, Cagliari ; Lisbon, CFTP ; Lisbon, IST) ; Veenhof, R. (Cagliari U. ; INFN, Cagliari ; Lisbon, CFTP ; Lisbon, IST) ; Wohri, H.K. (Cagliari U. ; INFN, Cagliari) |
| Publication | 2009 |
| Imprint | 17 Dec 2008 |
| Number of pages | 10 |
| Note | Comments: 10 pages, 12 figures, submitted to Eur. Phys. J. C 10 pages, 12 figures, submitted to Eur. Phys. J. C |
| In: | Eur. Phys. J. C 61 (2009) 711-720 |
| DOI | 10.1140/epjc/s10052-009-0878-5 |
| Subject category | Nuclear Physics - Experiment |
| Accelerator/Facility, Experiment | CERN SPS ; NA60 |
| 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<M<2.6 GeV. The mass spectrum for M<1 GeV is consistent with a dominant contribution from pi+pi- -> 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. |
Corresponding record in: Inspire
Record created 2008-12-17, last modified 2023-03-14
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