An improved calculation of the D(s)* D(s) V and B(s)* B(s) V couplings from light-cone sum rules

We present an improved calculation of the D-(s)* D-(s) V and B-(s)* B-(s) V coupling constants, where V denotes rho, K*, omega, and phi mesons. These couplings govern the long-distance quantum chromodynamics (QCD) in interactions between heavy pseudo-scalar/vector mesons and light vector mesons. Our analysis is conducted within the framework of QCD light-cone sum rules (LCSRs) by utilizing the light-cone distribution amplitudes (LCDAs) of light vector mesons. By systematically incorporating the subleading power corrections and higher-twist contributions at the leading order (LO) and including the next-to-leading order (NLO) corrections at leading power, we achieve enhanced accuracy in the light-cone operator product expansion (OPE) for the underlying correlation function. In assessing the reliability of the established LCSRs, we consider uncertainties arising from the choice of the quark-hadron duality region in the double dispersion relation. Building upon these improvements, we accomplish an optimized computation and analysis for the strong coupling constants g(H* H V) which are used to extract the effective coupling lambda in the heavy meson chiral perturbation theory (HM chi PT). Furthermore, we investigate the SU (3) flavor symmetry-breaking effects in detail and compare our sum rule calculations with previous studies in an exploratory way.