Transverse momentum dependence of J/psi shadowing effects

Abstract

We present a new approach to estimate the effect of the gluon shadowing in nucleus+nucleus collisions and its consequences on the J/psi production yield. Using kinematical information available from the measured J/psi production in proton+proton collisions at \sqrt s = 200 GeV, we build a Glauber Monte Carlo code which takes into account shadowing in two alternative ways: multiple scattering corrections or Q2 evolution of parton densities. We exploit the dependence of these different parameterizations to the J/psi transverse momentum and we give the first predictions on the resulting pT dependence of the nuclear modification factor in deuteron+gold collisions at the same energy.

Figures (4)

• Figure 1: $J/\psi$ rapidity and $p_{T}$ distributions in $p+p$ collisions extracted from Adare:2006kf. Vertical scales are arbitrary units.
• Figure 2: Nuclear modification factor as a function of rapidity from CF (top) and EKS (bottom) models. Three input $p+p$$p_{T}$ distributions are used: $p_{T}$=0, $p_{T}$ from $|y|<0.35$ and $p_{T}$ from $1.2<|y|<2.2$.
• Figure 3: Nuclear modification factor as a function of the number of collisions from CF (left) and EKS (right) models. From up to down: backward ($-2.2<y<-1.2$), central ($|y|<0.35$) and forward ($1.2<y<2.2$) rapidity regions.
• Figure 4: Nuclear modification factor as a function of the $J/\psi$ transverse momentum from CF (left) and EKS (right) models. From up to down: backward ($-2.2<y<-1.2$), central ($|y|<0.35$) and forward ($1.2<y<2.2$) rapidity regions.