Eur. Phys. J. C 21, 63-79 (2001)
One-loop leading logarithms in electroweak radiative corrections
II. Factorization of collinear singularitiesA. Denner1 and S. Pozzorini1, 2
1 Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
2 Institute of Theoretical Physics, University of Zürich, Zürich, Switzerland
(Received: 4 May 2001 / Published online: 6 July 2001 -© Springer-Verlag / Società Italiana di Fisica 2001 )
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