Nucleon resonances in omega photoproduction

Abstract

The role of the nucleon resonances ($N^{\ast }$) in $\omega$ photoproduction is investigated by using the resonance parameters predicted by Capstick and Roberts [Phys. Rev. D {\bf 46}, 2864 (1992); {\bf 49}, 4570 (1994)]. In contrast with the previous investigations based on the $SU(6)\times O(3)$ limit of the constituent quark model, the employed $N^{\ast }\to \gamma N$ and $N^{\ast }\to \omega N$ amplitudes include the configuration mixing effects due to the residual quark-quark interactions. The contributions from the nucleon resonances are found to be significant relative to the non-resonant amplitudes in changing the differential cross sections at large scattering angles and various spin observables. In particular, we suggest that a crucial test of our predictions can be made by measuring the parity asymmetry and beam-target double asymmetry at forward scattering angles.

Comments: 18 pages, REVTeX, 8 figures, to appear in Phys. Rev. C