Prospects for Backward Angle ($u$-channel) Physics at the Electron-Ion Collider

Backward ($u$-channel) production of vector mesons in $ep$ collisions is characterized by a final state consisting of a nearly-stopped proton and a vector meson with a large forward momentum. In conventional (forward, $t$-channel) production, the momentum transfer from the proton to the meson is small and is modeled by pomeron-exchange trajectories. The less well-understood $u$-channel production is modeled by a baryon-exchange trajectory and can provide unique insight into the nucleon wave function and inform contributions to baryon stopping in heavy-ion collisions. The Electron-Ion Collider presents the nuclear physics community with an opportunity to measure $u$-channel production at higher center-of-mass energies than previously available. Measurements of backwards-production events require far-forward detectors for observing high-rapidity mesons. eSTARlight, a code for modeling vector-meson production, is used to simulate backward-production events at the EIC. Several production channels will be analyzed at the known EIC collision energies, and detection capabilities for proposed detector designs will be assessed.