Consequences of nuclear shadowing for heavy quarkonium production in hadron-nucleus interactions

We study nuclear shadowing in J/ψ and Υ production in hadron-nucleus interactions and in nucleus-nucleus collisions at the Relativistic Heavy Ion Collider and the Large Hadron Collider. As a consequence of the perturbative ${\mathit{Q}}^2$ dependence of gluon shadowing, we predict that Υ production is less suppressed than the J/ψ. We show that antishadowing leads to enhanced J/ψ production at ${\mathit{x}}_{\mathit{f}}$≲0, an effect reduced for Υ production.