$\omega$ photoproduction within a novel unitary isobar model

The $\omega$ photoproduction off proton is analyzed within a novel unitary isobar model constructed based on the recent work by Razavi and Nakayama [Phys. Rev. D 100, 114036], where the full complex phase structure of the meson-baryon as well as the meson photoproduction amplitudes have been exposed. In this model unitarity is preserved through the so-called generalized Watson's factor. Moreover, apart from the usual $u$ and $t$-channel Feynman diagrams, we include a generalized contact current in the driving potential in the background amplitude, which guarantees the local gauge invariance of the resulting full amplitude by satisfying the Ward-Takahashi identity. The analysis considers the currently available high-precision cross section as well as the nine independent spin observables data, especially from the CLAS Collaboration.