The $H^{\ast }{H}^{\ast }V$ charge couplings from light-cone sum rules

Abstract

We present an updated and rigorous determination of the strong charge couplings $g_{H^{\ast }{H}^{\ast }V}$ (with $H\in \{D,B\}$ and $V\in \{\rho ,\omega ,K^{\ast },\varphi \}$) using the framework of light-cone sum rules (LCSR). The theoretical precision is significantly enhanced by establishing the leading-power hard-collinear factorization formula with next-to-leading-order (NLO) ${\alpha }_s$ corrections, alongside the systematic inclusion of power-suppressed contributions up to the next-to-next-to-leading power (NNLP). Our numerical analysis demonstrates a subtle cancellation of the factorization-scale dependence at NLO and reveals highly stable Borel plateaus, yielding robust predictions for the couplings. By parameterizing the $\mathcal{O}(1/m_{H^{\ast }})$ power corrections, we extract the universal static coupling $\beta =0.73\pm 0.13$ and demonstrate that these charge couplings are remarkably insensitive to heavy-quark mass breaking effects. Finally, our investigation into SU(3) flavor symmetry breaking shows that its minute physical effects are currently overshadowed by uncertainties in the non-perturbative vector meson distribution amplitudes.

Comments: 25 pages, 2 figures