The D∗Dπ and B∗Bπ couplings from light-cone sum rules

• Published in: The journal of high energy physics Vol. 2021; no. 3; pp. 16 - 41
• Main Authors: Khodjamirian, Alexander, Melić, Blaženka, Wang, Yu-Ming, Wei, Yan-Bing
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.03.2021; Springer Nature B.V; SpringerOpen
• Subjects: Accuracy; Approximation; Charm (particle physics); Classical and Quantum Gravitation; Couplings; Decay rate; Elementary Particles; Gluons; High energy physics; Light; Mathematical analysis; Mesons; NLO Computations; Physics; Physics and Astronomy; Pions; QCD Phenomenology; Quantum chromodynamics; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular - Theoretical Physics; Regular Article - Theoretical Physics; Relativity Theory; String Theory; Sum rules; NLO Computations; QCD Phenomenology
• ISSN: 1029-8479; 1126-6708; 1029-8479
• DOI: 10.1007/JHEP03(2021)016

A bstract We revisit the calculation of the strong couplings D ∗ Dπ and B ∗ Bπ from the QCD light-cone sum rules using the pion light-cone distribution amplitudes. The accuracy of the correlation function, calculated from the operator product expansion near the light-cone, is upgraded by taking into account the gluon radiative corrections to the twist-3 terms. The double spectral density of the correlation function, including the twist-2, 3 terms at O α s and the twist-4 LO terms, is presented in an analytical form for the first time. This form allows us to use various versions of the quark-hadron duality regions in the double dispersion relation underlying the sum rules. We predict g D ∗ Dπ = 14.1 − 1.2 + 1.3 and g B ∗ Bπ = 30.0 − 2.4 + 2.6 when the decay constants of heavy mesons entering the light-cone sum rule are taken from lattice QCD results. We compare our results with the experimental value for the charmed meson coupling and with the lattice QCD calculations.