Partial next-to-next-to-leading-order corrections to the B → π form factors from light-cone sum rules
Year: 2026
Type: article
Abstract: A bstract By incorporating the available leading-power results at $$ \mathcal{O}\left({\alpha}_s\right) $$ O α s and next-to-leading-power corrections at tree level, we compute the $$ \mathcal{O}\left({\alpha}_s^2{\beta}_0\right) $$ O α s 2 β 0 contribution to the B → π form factors in the large-recoil region using the light-cone sum rule approach with B -meson light-cone distribution amplitudes. We find that the QCD corrections at $$ \mathcal{O}\left({\alpha}_s^2{\beta}_0\right) $$ O α s 2 β 0 contribute approximately +6.1% compared to the tree-level result. Combining the light-cone sum rule predictions in the large-recoil region, lattice QCD results in the small-recoil region, we perform a combined fit for the B → π form factors across the full kinematic range. Utilizing these form factors, we update the branching ratios, lepton-flavor-universality ratio R π , forward-backward asymmetry $$ {\mathcal{A}}_{\mathrm{FB}} $$ A FB , flat term $$ {\mathcal{F}}_{\mathrm{H}} $$ F H and polarization asymmetry $$ {\mathcal{A}}_{\lambda_{\ell }} $$ A λ ℓ of $$ B\to \pi \mu {\overline{\nu}}_{\mu } $$ B → πμ ν ¯ μ and $$ B\to \pi \tau {\overline{\nu}}_{\tau } $$ B → πτ ν ¯ τ decays. We also extract the Cabibbo-Kobayashi-Maskawa matrix element | V ub | = 3.73(14) × 10 −3 . We find that the resulting shifts are generally small and remain within the uncertainties of previous analyses.
Source: Journal of High Energy Physics
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7117102806