Eur. Phys. J. C 21, 63-79 (2001)
DOI: 10.1007/s100520100721
One-loop leading logarithms in electroweak radiative corrections
II. Factorization of collinear singularities
A. Denner1 and S. Pozzorini1, 21 Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
2 Institute of Theoretical Physics, University of Zürich, Zürich, Switzerland
Ansgar.Denner@psi.ch
pozzorin@physik.unizh.ch
(Received: 4 May 2001 / Published online: 6 July 2001 -© Springer-Verlag / Società Italiana di Fisica 2001 )
Abstract
We discuss the evaluation of the collinear single-logarithmic
contributions to virtual electroweak corrections at high energies.
More precisely, we prove the factorization of the mass singularities
originating from loop diagrams involving collinear virtual gauge
bosons coupled to external legs. We discuss, in particular, processes
involving external longitudinal gauge bosons, which are treated using
the Goldstone-boson equivalence theorem. The proof of factorization
is performed within the 't Hooft-Feynman gauge at one-loop order and
applies to arbitrary electroweak processes that are not
mass-suppressed at high energies. As basic ingredients we use Ward
identities for Green functions with arbitrary external particles
involving a gauge boson collinear to one of these. The Ward identities
are derived from the BRS invariance of the spontaneously broken
electroweak gauge theory.
© Società Italiana di Fisica, Springer-Verlag 2001