Chiral expansion for lattice computations of B^{+} to D^{0}K^{+} (\pi^{+}) and B^{+} to Dbar^{0} K^{+} (\pi^{+}) amplitudes

TL;DR

This paper explores the application of hard-pion chiral perturbation theory to compute the real parts of nonleptonic B+ decay amplitudes involving D and K/π mesons, aiding CKM matrix angle measurements.

Contribution

It introduces a leading-order chiral operator for B+ to D0P+ decays and discusses next-to-leading-order features relevant for lattice QCD calculations.

Findings

Chiral perturbation theory can be applied to nonleptonic B decays.

Constructed leading-order operators for decay amplitudes.

Discussed the structure of higher-order corrections.

Abstract

In this work, we suggest that hard-pion chiral perturbation theory may be applicable to the real parts of nonleptonic B^{+} to D^{0}P^{+} and B^{+} to Dbar^{0}P^{+} (P=K,pi) decay amplitudes. These amplitudes play an important role in the extraction of the angle gamma in the b-d unitarity triangle of the CKM matrix, and their real parts can be computed using lattice QCD. We construct the leading-order operator in the chiral expansion for these nonleptonic decays, and discuss the generic features of the next-to-leading-order terms.