Phenomenological evidence for gluon depletion in pA collisions

The data of J/psi suppression at large x(F) in pA collisions are used to infer the existence of gluon depletion as the projectile proton traverses the nucleus. The modification of the gluon distribution is studied by use of a convolution equation whose nonperturbative splitting function is determined phenomenologically. The depletion factor at x(1) = 0.8 is found to be about 25% at A = 100.