Unstable Particles and Gauge Invariance
High Energy Physics - Phenomenology
2007-05-23 v1
Abstract
When computing the properties of reactions involving unstable charged particles care has to be taken to use a gauge invariant amplitude. In this talk we present methods to (automatically) obtain such an amplitude, both at the tree level and in one-loop calculations, using only a minimal number of diagrams. The numerical difference with gauge variant methods commonly used will be discussed for the case of tree level W pair production.
Cite
@article{arxiv.hep-ph/9311223,
title = {Unstable Particles and Gauge Invariance},
author = {Geert Jan van Oldenborgh},
journal= {arXiv preprint arXiv:hep-ph/9311223},
year = {2007}
}
Comments
6 pages, 2 figures appended, needs axodraw,epsf. The whole ps file is available with anonymous ftp from pss058.psi.ch in /pub/preprints/ as unstablepart.ps[.Z]. Proceedings of the 3rd workshop for SI and AI in HEP, Oberammergau, PSI-PR-93-19