The omega rho pi coupling in the VMD model revisited

TL;DR

This paper revisits the  coupling constant in the vector meson dominance model by analyzing various decay processes and cross sections, considering additional resonances and contact terms to refine its value.

Contribution

It provides a new, more precise determination of the -- coupling constant, accounting for heavier resonances and contact interactions in the analysis.

Findings

Estimated g_{ ho\u03c0} b14.7 b1 0.1 GeV^{-1} without additional contributions.

Including ' or contact terms reduces the coupling estimate to b11.9 b1 0.2 GeV^{-1} or b11.7 b1 0.1 GeV^{-1}.

Additional terms lead to more consistent estimates across different observables.

Abstract

We determine the value of the \omega -\rho- \pi mesons coupling (g_{\omega\rho\pi}), in the context of the vector meson dominance model, from radiative decays, the \omega \rightarrow 3\pi decay width and the e^+e^- \rightarrow 3\pi cross section. For the last two observables we consider the effect of either a heavier resonance (\rho'(1450)) or a contact term. A weighted average of the results from the set of observables yields g_{\omega\rho\pi} =14.7 \pm 0.1 GeV^{-1} in absence of those contributions, and g_{\omega\rho\pi} =11.9 \pm 0.2 GeV^{-1} or g_{\omega\rho\pi} =11.7 \pm 0.1 GeV^{-1} when including the \rho' or contact term respectively. The inclusion of these additional terms makes the estimates from the different observables to lay in a more reduced range. Improved measurements of these observables and the \rho'(1450) meson parameters are needed to give a definite answer on the pertinence of the inclusion of this last one in the considered processes.