$\omega$-Meson Photoproduction on Nucleons In the Near Threshold Region

Abstract

The $\omega$-meson photoproduction, $\gamma +p\to p+\omega$, is studied in the framework of a model, containing $\pi$-meson exchange in t-channel and nucleon-exchange in s- and u-channels. Considering both $\omega NN$-coupling constants in the region of time-like meson four momenta as the free parameters, we find different sets of solutions for these constants from the existing data on the t-dependence of the differential cross sections, $d\sigma (\gamma +p\to p+\omega )/dt$, in the near threshold region $E_{\gamma }\le 2$ GeV. These sets of $\omega NN$-coupling constants, corresponding to destructive and constructive $\pi ⨂N$-interference contributions to $d\sigma /dt$ can be well distinguished by measurements of beam asymmetry, induced by linear photon polarization.

Comments: 29 pages, RevTex, 6 PS Figures