Chiral symmetry and exclusive B decays in the SCET

We construct a chiral formalism for processes involving both energetic hadrons and soft Goldstone bosons, which extends the application of soft-collinear effective theory to multibody B decays. The nonfactorizable helicity amplitudes for heavy meson decays into multibody final states satisfy symmetry relations analogous to the large energy form factor relations, which are broken at leading order in Lambda/mb by calculable factorizable terms. We use the chiral effective theory to compute the leading corrections to these symmetry relations in B -> Mn pi lv and B -> Mn pi l(+)l(-) decays, with one energetic meson M-n and one soft pion. (c) 2005 Elsevier B.V All rights reserved.