1 research outputs found
Nucleonic resonance excitations with linearly polarized photon in
In this work, an improved quark model approach to the meson
photo-production with an effective Lagrangian is presented. The {\it t}-channel
{\it natural}-parity exchange is taken into account through the Pomeron
exchange, while the {\it unnatural}-parity exchange is described by the
exchange. With a very limited number of parameters, the available experimental
data in the low energy regime can be consistently accounted for. We find that
the beam polarization observables show sensitivities to some {\it s}-channel
individual resonances in the quark model symmetry limit.
Especially, the two resonances and , which belong
to the representation , have dominant contributions
over other excited states. Concerning the essential motivation of searching for
"missing resonances" in meson photo-production, this approach provides a
feasible framework, on which systematic investigations can be done.Comment: 16 pages, Revtex, 9 eps figures, to appear in PR