Details

Autor(en) / Beteiligte

• Gao, Jing
• Lü, Cai-Dian
• Shen, Yue-Long
• Wang, Yu-Ming
• Wei, Yan-Bing

Titel

Precision calculations of B → V form factors from soft-collinear effective theory sum rules on the light-cone

Ist Teil von

• Physical review. D, 2020-04, Vol.101 (7), p.1, Article 074035

Ort / Verlag

College Park: American Physical Society

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Applying the vacuum-to- B -meson correlation functions with an interpolating current for the light vector meson we construct the light-cone sum rules (LCSR) for the "effective" form factors ξ∥ ( n ⋅ p ) , ξ⊥ ( n ⋅ p ) , Ξ∥ ( τ , n ⋅ p ) and Ξ⊥ ( τ , n ⋅ p ) , defined by the corresponding hadronic matrix elements in soft-collinear effective theory (SCET), entering the leading-power factorization formulas for QCD form factors responsible for B → V ℓνℓ and B → Vℓℓ decays at large hadronic recoil at next-to-leading-order in QCD. The evanescent-operator approach for the perturbative matching of the effective operators from SCETI → HQET is employed in the determination of the hard-collinear functions entering the SCET factorization formulas for the vacuum-to- B -meson correlation functions. The light-quark mass effect for the local SCET form factors ξ∥ ( n ⋅ p ) and ξ⊥ ( n ⋅ p ) is also computed from the LCSR method with the B -meson light-cone distribution amplitude ϕ+B ( ω , μ ) at O (αs) . Furthermore, the subleading power corrections to B → V form factors from the higher-twist B -meson light-cone distribution amplitudes are also computed with the same method at tree level up to the twist-six accuracy. Employing the two different models for the B -meson light-cone distribution amplitudes consistent with QCD equations of motion, we observe that the higher-twist corrections to B → V form factors are dominated by the two-particle twist-five distribution amplitude g−B ( ω , μ ) , in analogy to the previous observation for B → P form factors. Having at our disposal the LCSR predictions for B → V form factors, we further perform new determinations of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element |Vub| from the semileptonic B → ρℓνℓ and B → ωℓνℓ decays, and predict the normalized differential branching fractions and the q2 -binned K ∗ longitudinal polarization fractions of the exclusive rare B → K∗νℓνℓ decays.