Precision calculations of the D (s) D (s) V and B (s) B (s) V couplings from light-cone sum rules

Abstract

Abstract We present an improved calculation of the HHV (H = D (s), B (s), V = ρ, K *, ω, and ϕ) coupling constants g HHV beyond leading order in α s from QCD light-cone sum rules (LCSRs) by means of the light-cone distribution amplitudes (LCDAs) of light vector mesons. Near the light-cone, the next-to-leading order QCD corrections for the vacuum-to-vector-meson correlation function are included at leading power in δ V = m V /m Q (Q = b, c) within the framework of hard-collinear factorization. The higher-twist corrections from two-particle and three-particle vector meson LCDAs are systematically incorporated at leading order in α s by applying the method of background field in LCSRs. Based on these improvements, we perform a systematic computation of the strong coupling constants g HHV and extract the effective coupling β of the heavy meson chiral perturbation theory (HMχPT). Furthermore, we accomplish the analysis for the relation between the coupling g HHV and the residue of the H → V transition form factor A 0 at heavy pseudoscalar pole. Additionally, we provide a detailed investigation of the SU(3) flavour symmetry breaking effects and conduct a comparative analysis with results from previous studies.

Keywords

• The Strong Coupling
• Factorization
• Renormalization Group
• Effective Field Theories of QCD