Photoproduction of the ρ0 Meson on the Proton at Large Momentum Transfer

The differential cross section, dσ/dt, for ρ0 meson photoproduction on the proton above the resonance region was measured up to a momentum transfer −t=5GeV2 using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The ρ0 channel was extracted from the measured two charged-pion cross sections by fitting the π+π− and pπ+ invariant masses. The low momentum transfer region shows the typical diffractive pattern expected from Reggeon exchange. The flatter behavior at large −t cannot be explained solely in terms of QCD-inspired two-gluon exchange models. The data indicate that other processes, like quark interchange, are important to fully describe ρ photoproduction.