Radiative Corrections on the $B\to P$ Form Factors with Chiral Current in the Light-Cone Sum Rules

TL;DR

This paper extends the calculation of radiative corrections to $B o P$ form factors using light-cone sum rules, reducing uncertainties and providing precise form factor values at zero momentum transfer.

Contribution

It introduces a method to eliminate twist-3 uncertainties and presents next-leading-order formulas for $B o P$ form factors with improved accuracy.

Findings

Calculated form factors at $q^2=0$ with uncertainties.

Reduced theoretical uncertainties by eliminating twist-3 contributions.

Discussed SU(3) flavor symmetry breaking effects.

Abstract

Based on the approach of the vector form factor $F^{+}_{B\to\pi, K}(q^2)$ in our previous papers, we extend the calculation of the radiative corrections to the $B\to P$ ($P$ stands $\pi$, $K$ and all light pseudoscalar mesons) scalar and tensor form factors $F^{0,T}_{B\to P}(q^2)$ with chiral current in the light-cone sum rules (LCSRs). The most uncertain twist-3 contributions to the $B\to P$ form factors can be naturally eliminated through a properly designed correlator. We present the next-leading-order formulae of $F^{+,0,T}_{B\to P}(q^2)$ with the $b$-quark pole mass that is universal. It has been shown that our results are simpler and less uncertain under the same parameter regions since we only need to calculate the next leading order on the twist-2 part from the obtained LCSR. Second, we obtain $f^{+,0}_{B\to\pi}(0)=0.260^{+0.059}_{-0.040}$, $f^{T}_{B\to\pi}(0)=0.276^{+0.052}_{-0.039}$, $f^{+,0}_{B\to K}(0)=0.334^{+0.094}_{-0.069}$ and $f^{T}_{B\to K}(0) =0.379^{+0.092}_{-0.077}$ at $q^2=0$ and the $SU_f(3)$-breaking effects are discussed too.