QCD factorization for the four-body leptonic B-meson decays

• Published in: The journal of high energy physics Vol. 2022; no. 2; pp. 141 - 54
• Main Authors: Wang, Chao, Wang, Yu-Ming, Wei, Yan-Bing
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.02.2022; Springer Nature B.V; SpringerOpen
• Subjects: Classical and Quantum Gravitation; Elementary Particles; Factorization; Form factors; Heavy Quark Physics; High energy physics; Leptons; Logarithms; Particle decay; Perturbative QCD; Photons; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Quarks; Regular Article - Theoretical Physics; Relativity Theory; Resummation; String Theory; Heavy Quark Physics; Resummation; Perturbative QCD
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP02(2022)141

A bstract Employing the QCD factorization formalism we compute B u − → γ ∗ ℓ v ¯ ℓ form factors with an off-shell photon state possessing the virtuality of order m b Λ QCD and m b 2 , respectively, at next-to-leading order in QCD. Perturbative resummation for the enhanced logarithms of m b /Λ QCD in the resulting factorization formulae is subsequently accomplished at next-to-leading logarithmic accuracy with the renormalization-group technique in momentum space. In particular, we derive the soft-collinear factorization formulae for a variety of the subleading power corrections to the exclusive radiative B u − → γ ∗ W ∗ form factors with a hard-collinear photon at O α s 0 . We further construct a complete set of the angular observables governing the full differential distribution of the four-body leptonic decays B u − → ℓ ′ ℓ ¯ ′ ℓ v ¯ ℓ with ℓ , ℓ′ ∈ { e , μ } and then perform an exploratory phenomenological analysis for a number of decay observables accessible at the LHCb and Belle II experiments, with an emphasis on the systematic uncertainties arising from the shape parameters of the leading-twist B -meson light-cone distribution amplitude in heavy quark effective theory.