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Nucleonic resonance effects in the $ϕ$ meson photoproduction

Q. Zhao·J. -P. Didelez·M. Guidal·B. Saghai
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Abstract

The process $γp \to ϕp$ close to threshold is investigated focusing on the role played by the {\it s}- and {\it u}-channel nucleonic resonances. For this purpose, a recent quark model approach, based on the $SU(6)\otimes O(3)$ symmetry with an effective Lagrangian, is extended to the $ϕ$ meson photoproduction. Another non-diffractive process, the {\it t}-channel $π^0$ exchange, is also included. The diffractive contribution is produced by the {\it t}-channel Pomeron exchange. Contributions from non-diffractive {\it s}- and {\it u}-channel process are found small in the case of cross sections and polarization observables at forward angles. However, backward angle polarization asymmetries show high sensitivity to this non-diffractive process. Different prescriptions to keep gauge invariance for the Pomeron exchange amplitudes are investigated. Possible deviations from the exact $SU(6)\otimes O(3)$ symmetry, due to the configuration mixing, are also discussed.

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Q. Zhao, J. -P. Didelez, M. Guidal, B. Saghai. 1999-09-22. Nucleonic resonance effects in the $ϕ$ meson photoproduction. https://doi.org/10.1016/s0375-9474(99)00398-x

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