Holographic J/Ψ production near threshold and the proton mass problem

It has been suggested that the production of a heavy quarkonium near threshold in electron- proton scattering can shed light on the origin of the proton mass via the QCD trace anomaly. We study the photoproduction of J/Ψ off the proton using gauge/string duality and demonstrate that the t-dependence of the differential cross section d/dt at small-t is a sensitive probe of the trace anomaly.