Finite-energy sum rules in eta photoproduction off a nucleon

Abstract

The reaction $\ensuremath{\gamma}N\ensuremath{\rightarrow}\ensuremath{\eta}N$ is studied in the high-energy regime (with photon lab energies ${E}_{\ensuremath{\gamma}}^{\mathrm{lab}}>4\text{ }\text{ }\mathrm{GeV}$) using information from the resonance region through the use of finite-energy sum rules. We illustrate how analyticity allows one to map the $t$ dependence of the unknown Regge residue functions. We provide predictions for the energy dependence of the beam asymmetry at high energies.