Nonleptonic B decays into two light mesons in soft-collinear effective theory
arXiv:hep-ph/0301262 · doi:10.1016/j.nuclphysb.2003.12.027
Abstract
We consider nonleptonic B decays into two light mesons at leading order in soft-collinear effective theory, and show that the decay amplitudes are factorized to all orders in alpha_s. The operators for nonleptonic B decays in the full theory are first matched to the operators in SCET_I, which is the effective theory appropriate for sqrt{m_b Lambda} <mu <m_b with Lambda~0.5 GeV. We evolve the operators and the relevant time-ordered products in SCET_I to SCET_II, which is appropriate for mu < sqrt{m_b Lambda}. Using the gauge-invariant operators in SCET_II, we compute nonleptonic B decays in SCET, including the nonfactorizable spectator contributions and spectator contributions to the heavy-to-light form factor. As an application, we present the decay amplitudes for B ->pi,pi in soft-collinear effective theory.
42 pages, 5 figures, 2 tables Major revision of the manuscript. The idea of using SCET_I, and SCET_II is clearly presented. Some of the calculational steps are explicitly shown