210 articles – 1947 Notices  [english version]
 HAL : in2p3-00624015, version 1
 arXiv : 1107.4630
 Physical Review C 85 (2012) 014910
 $\rho^{0}$ Photoproduction in AuAu Collisions at $\sqrt{s_{NN}}$=62.4 GeV with STAR
 STAR Collaboration(s)
 (2012)
 Vector mesons may be photoproduced in relativistic heavy-ion collisions when a virtual photon emitted by one nucleus scatters from the other nucleus, emerging as a vector meson. The STAR Collaboration has previously presented measurements of coherent $\rho^0$ photoproduction at center of mass energies of 130 GeV and 200 GeV in AuAu collisions. Here, we present a measurement of the cross section at 62.4 GeV; we find that the cross section for coherent $\rho^0$ photoproduction with nuclear breakup is $10.5\pm1.5\pm 1.6$ mb at 62.4 GeV. The cross-section ratio between 200 GeV and 62.4 GeV is $2.8\pm0.6$, less than is predicted by most theoretical models. It is, however, proportionally much larger than the previously observed $15\pm 55$% increase between 130 GeV and 200 GeV.
 Thème(s) : Physique/Physique des Hautes Energies - ExpériencePhysique/Physique Nucléaire Expérimentale
 Lien vers le texte intégral : http://fr.arXiv.org/abs/1107.4630
 in2p3-00624015, version 1 http://hal.in2p3.fr/in2p3-00624015 oai:hal.in2p3.fr:in2p3-00624015 Contributeur : Dominique Girod <> Soumis le : Jeudi 15 Septembre 2011, 15:41:24 Dernière modification le : Mercredi 1 Février 2012, 08:13:56