212 articles – 1958 Notices  [english version]
 HAL : in2p3-00272463, version 1
 arXiv : 0707.2944
 Physics Letters B 660 (2008) 181-187
 Measuring gluon shadowing with prompt photons at RHIC and LHC
 F. Arleo1, 2, T. Gousset3
 (2008)
 The possibility to observe the nuclear modification of the gluon distribution at small-x (gluon shadowing) using high-p_T prompt photon production at RHIC and at LHC is discussed. The per-nucleon ratio, sigma(p+A -> gamma+X) / A sigma(p+p -> gamma+X), is computed for both inclusive and isolated prompt photons in perturbative QCD at NLO using different parametrizations of nuclear parton densities, in order to assess the visibility of the shadowing signal. The production of isolated photons turns out to be a promising channel which allows for a reliable extraction of the gluon density, G^A/G^p, and the structure function, F_2^A/F_2^p, in a nucleus over that in a proton. Moreover, the production ratio of prompt photons at forward-over-backward rapidity in p-A collisions provides an estimate of G^A/G^p (at small x) over F_2^A/F_2^p (at large x), without the need of p-p reference data at the same energy.
 Thème(s) : Physique/Physique des Hautes Energies - Phénoménologie
 Mot(s)-clé(s) : Nuclear shadowing – prompt photons – proton–nucleus collisions
 Lien vers le texte intégral : http://fr.arXiv.org/abs/0707.2944
 in2p3-00272463, version 1 http://hal.in2p3.fr/in2p3-00272463 oai:hal.in2p3.fr:in2p3-00272463 Contributeur : Dominique Girod <> Soumis le : Vendredi 11 Avril 2008, 15:12:19 Dernière modification le : Vendredi 11 Avril 2008, 15:26:13