Spectator Interactions in Soft-Collinear Effective Theory
Abstract
Soft-collinear effective theory is generalized to include soft massless quarks in addition to collinear fields. This extension is necessary for the treatment of interactions with the soft spectator quark in a heavy meson. The power counting of the relevant fields and the construction of the effective Lagrangian are discussed at leading order in Lambda/m_b. Several novel effects occur in the matching of full-theory amplitudes onto effective-theory operators containing soft light quarks, such as the appearance of an intermediate mass scale and large non-localities of operators on scales of order 1/Lambda. Important examples of effective-theory operators with soft light quarks are studied and their renormalization properties explored. The formalism presented here forms the basis for a systematic analysis of factorization and power corrections for any exclusive B-meson decay into light particles.
Cite
@article{arxiv.hep-ph/0211018,
title = {Spectator Interactions in Soft-Collinear Effective Theory},
author = {Richard J. Hill and Matthias Neubert},
journal= {arXiv preprint arXiv:hep-ph/0211018},
year = {2010}
}
Comments
29 pages, 7 figures, version to appear in Nuclear Physics B