# Higher-Twist Effects in Light-Cone Sum Rule for the $B\to\pi$ Form Factor

## TL;DR

This paper calculates higher-twist corrections to the $B\to\pi$ form factor using light-cone sum rules, extending the quark propagator expansion and finding these effects are numerically suppressed, supporting the standard truncation at twist-4.

## Contribution

It introduces new terms in the quark propagator expansion for higher-twist effects and provides analytical expressions for twist-5 and twist-6 contributions in the sum rule framework.

## Key findings

- Higher-twist effects are strongly suppressed in the $B\to\pi$ form factor.
- Justifies truncation of the operator product expansion at twist-4.
- Provides analytical expressions for twist-5 and twist-6 contributions.

## Abstract

We calculate the higher-twist corrections to the QCD light-cone sum rule for the $B \to \pi$ transition form factor. The light-cone expansion of the massive quark propagator in the external gluonic field is extended to include new terms containing the derivatives of gluon-field strength. The resulting analytical expressions for the twist-5 and twist-6 contributions to the correlation function are obtained in a factorized approximation, expressed via the product of the lower-twist pion distribution amplitudes and the quark-condensate density. The numerical analysis reveals that new higher-twist effects for the $B \to \pi$ form factor are strongly suppressed. This result justifies the conventional truncation of the operator product expansion in the light-cone sum rules up to twist-4 terms.