Shadowing of gluons in perturbative QCD: A comparison of different models - art. no. 096001

We investigate the different perturbative QCD-based models for nuclear shad owing of gluons. We show that, in the kinematic region appropriate to the B NL relativistic heavy ion collider experiment, all models give similar esti mates for the magnitude of gluon shadowing. At scales relevant to CERN larg e hadron collider (LHC), there is a sizable difference between the predicti ons of the different models. However, the uncertainties in gluon shadowing coming from a different parametrization of the gluon distribution in nucleo ns, are larger than those due to different perturbative QCD models of gluon shadowing. We also investigate the effect of initial nonperturbative shado wing on the magnitude of perturbative shadowing and show that the magnitude s of perturbative and nonperturbative shadowing are comparable at RHIC but perturbative shadowing dominates over nonperturbative shadowing at smaller values of x reached at LHC.