  New GeV-scale dark forces coupling predominantly to quarks offer novel
signatures that can be produced directly and searched for at high-luminosity
colliders. We compute the photon-proton and electron-proton cross sections for
producing a GeV-scale gauge boson arising from a $U(1)_B$ gauge symmetry. Our
calculation relies on vector meson dominance and a phenomenological model for
diffractive scattering used for vector-meson photoproduction. The parameters of
our phenomenological model are fixed by performing a Markov Chain Monte Carlo
fit to existing exclusive photoproduction data for $\omega$ and $\phi$ mesons.
Our approach can be generalized to other GeV-scale dark gauge forces.
