Determination of the $g_{ρσγ}$ coupling constant through the process $γ+N\to N+V$ with circularly polarized photons

Abstract

We suggest a method to determine the product of the coupling constants $g_{ρσγ}g_ {σNN}$, in absolute value and relative sign, through the $t$-dependence of the two possible T-even asymmetries for the photoproduction of vector mesons, $γ+p\to p+V^0$, $V^0=ρ$ or $ω$, in the collision of circularly polarized photons with a polarized proton target. In the framework of a $π+σ$-model, these asymmetries are very sensitive to the relative role of $π$- and $σ$-exchanges, in the near threshold region.