Hidden self-energy contributions of collinear functions in SCET
Abstract
Motivated by the requirement of the LSZ reduction formula to remove self-energy contributions on external legs, we examine quark self-energy contributions in soft-collinear effective (SCET) theory. We examine an operator basis that follows directly from full quantum chromodynamics (QCD) (upon application of the SCET equations of motion to express small Dirac components in terms of large Dirac components). We find that, for this basis, the self-energy contributions can be identified from their diagrammatic topologies, as in full QCD. However, for an alternative operator basis that is obtained from the direct-QCD basis by an application of Wilson-line identities, interactions are shifted from a covariant derivative to a Wilson line. Consequently, some self-energy contributions are hidden in diagrams involving Wilson lines, making their identification subtle.
Keywords
Cite
@article{arxiv.2512.11647,
title = {Hidden self-energy contributions of collinear functions in SCET},
author = {Geoffrey T. Bodwin and June-Haak Ee and Daekyoung Kang and Xiang-Peng Wang},
journal= {arXiv preprint arXiv:2512.11647},
year = {2026}
}
Comments
22 pages, 4 figures, Version submitted to Physical Review D