Production of [ital J]/[psi] at large [ital x][sub [ital F]] in 800 GeV/[ital c] [ital p]-copper and [ital p]-beryllium collisions

The differential cross sections [ital d][sigma]/[ital dx][sub [ital F]] for [ital J]/[psi] produced inclusively in 800 GeV/[ital c] [ital p]-Cu and [ital p]-Be collisions have been measured in the kinematic range 0.30[le][ital x][sub [ital F]][le]0.95 through the decay mode [ital J]/[psi][r arrow][mu][sup +][mu][sup [minus]]. They are compared with the predictions of the semilocal duality model for several sets of parton density functions. No evidence for a suggested intrinsic charm contribution to the cross section is observed. The ratio of the differential cross sections for Cu and Be targets confirms the suppression of [ital J]/[psi] production in heavy nuclei at large [ital x][sub [ital F]].