Sudakov Resummation for Subleading SCET Currents and Heavy-to-Light Form Factors.

Hill, R. J. ; Becher, T. ; Lee, S. J. ; Neubert, M.

Technical Information Center Oak Ridge Tennessee

关键词: Collinearity;    Form factors;    Anomalous dimension;    Perturbation theory;    Quantum chromodynamics;   

RP-ID  :  DE2004826913

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

The hard-scattering contributions to heavy-to-light form factors at large recoil are studied systematically in soft-collinear effective theory (SCET). Large logarithms arising from multiple energy scales are resummed by matching QCD onto SCET in two stages via an intermediate effective theory. Anomalous dimensions in the intermediate theory are computed, and their form is shown to be constrained by conformal symmetry. Renormalization-group evolution equations are solved to give a complete leading-order analysis of the hard-scattering contributions, in which all single and double logarithms are resummed. In two cases, spin-symmetry relations for the soft-overlap contributions to form factors are shown not to be broken at any order in perturbation theory by hard-scattering corrections.