Loop Corrections to Heavy-to-Light Form Factors and Evanescent Operators   in SCET
  One-loop matching corrections are calculated for Soft-Collinear Effective Theory (SCET) operators relevant to the analysis of heavy-to-light meson form factors at large recoil. The numerical impact of radiative corrections on form factor predictions is assessed. Evanescent operators in the effective theory are studied and it is shown that even in problems of the Sudakov type, these operators can be renormalized to have vanishing matrix elements. 
Thomas Becher and Richard J. Hill