Reggeized model for $\gamma p \to \rho^- \Delta^{++}(1232)$ photoproduction

Abstract

A model for the reaction $\gamma p\to\rho^-\Delta^{++}$ is presented with the $t$-channel $\pi+\rho$ exchanges reggeized to describe the reaction up to high energies. Gauge invariance of $\rho$ exchange is discussed in connection with the convergence of the reaction cross section at high energy. The roles of electromagnetic (EM) multipole moments of $\Delta^{++}$ baryon and of $\rho^-$ meson are analyzed in total and differential cross sections and spin density matrix elements. Photon polarization asymmetry $\Sigma$ is predicted for a measurement of electromagnetic moments of $\rho^-$ and of $\Delta^{++}$.