Soft-Collinear Factorization and Sudakov Resummation of Heavy Meson   Decay Amplitudes with Effective Field Theories
  In this thesis we present an introduction to Soft-Collinear Effective Theory, which can be used to prove (or disprove) factorization theorems to all orders in the strong coupling constant for some B decays into light and energetic particles. Specifically, the factorizable amplitudes for inclusive B->X_u l nu and exclusive B->gamma l nu are calculated in renormalization-group improved perturbation theory to first non-trivial order. Form factors encoding the exclusive decay amplitudes for B->P l nu and B->V l nu (P=light pseudoscalar meson, V=light vector meson) are studied and proved to be dominated by the non-factorizable Feynman mechanism. 
Bjorn O Lange (Cornell)