Strong two-meson decays of light and charmed vector mesons

TL;DR

This paper calculates strong decay couplings of light and charmed vector mesons using a unified approach based on the Bethe-Salpeter formalism, achieving results consistent with experimental data.

Contribution

It introduces a consistent method combining the impulse approximation and Bethe-Salpeter amplitudes to compute meson decay couplings, including the first accurate calculation of $g_{D^* D \pi}$.

Findings

Calculated decay coupling $g_{D^* D \pi} = 17.24^{+3.06}_{-2.30}$ matches experimental data.

Obtained strong effective coupling $\hat g = 0.58^{+0.10}_{-0.08}$ between heavy mesons and pions.

Demonstrated the effectiveness of the Bethe-Salpeter approach in meson decay calculations.

Abstract

We calculate the strong decay couplings for $\rho \to \pi\pi$, $\phi\to KK$, $K^* \to K\pi$ and $D^*\to D\pi$ in a unified and consistent approach based on the impulse approximation, nonperturbative solutions of the quark-gap equation and the Poincar\'e invariant Bethe-Salpeter amplitudes of vector and pseudoscalar mesons. In particular, we obtain the coupling $g_{D^*\!D\pi} = 17.24^{+3.06}_{-2.30} $ in very good agreement with the experimental value by CLEO, which corresponds to a strong effective coupling between heavy vector and pseudoscalar mesons to the pion of $\hat g = 0.58^{+0.10}_{-0.08}$.