Chiral expansion for lattice computations of B^{+} to D^{0}K^{+}   (\pi^{+}) and B^{+} to Dbar^{0} K^{+} (\pi^{+}) amplitudes
  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. 
Christopher Aubin, C.-J. David Lin, Amarjit Soni
hep-lat hep-ph