English

Light-cone sum rules in soft-collinear effective theory

High Energy Physics - Phenomenology 2008-11-26 v4

Abstract

We derive light-cone sum rules (LCSRs) for exclusive B-meson decays into light energetic hadrons from correlation functions within soft-collinear effective theory (SCET). In these sum rules the short-distance scale refers to ``hard-collinear'' interactions with virtualities of order (Lambda_{QCD}*m_b). Hard scales (related to virtualities of order m_b^2) are integrated out and enter via external coefficient functions in the sum rule. Soft dynamics is encoded in light-cone distribution amplitudes for the B-meson, which describe both the factorizable and non-factorizable contributions to exclusive B-meson decay amplitudes. As an example, we provide a detailed study of the SCET sum rule for the B -> pi transition form factor at large recoil, including radiative corrections from hard-collinear loop diagrams at first order in the strong coupling constant. We find remarkable conceptual and numerical differences with the heavy-quark limit of the conventional LCSR approach in QCD.

Keywords

Cite

@article{arxiv.hep-ph/0504088,
  title  = {Light-cone sum rules in soft-collinear effective theory},
  author = {Fulvia De Fazio and Thorsten Feldmann and Tobias Hurth},
  journal= {arXiv preprint arXiv:hep-ph/0504088},
  year   = {2008}
}

Comments

34 pages, 9 figures, erratum added

R2 v1 2026-07-22T14:01:22.219Z