https://doi.org/10.1140/epjc/s2003-01313-3
theoretical physics
Forests, groves and Higgs bosons
Gauge invariance classes in spontaneously broken gauge theories
1
Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
2
Institut für Kernphysik, Darmstadt University of Technology, Schloßgartenstr. 9, 64289, Darmstadt, Germany
* e-mail: ohl@physik.uni-wuerzburg.de
We determine the gauge invariance classes of tree level Feynman diagrams in spontaneously broken gauge theories, providing a proof for the formalism of gauge and flavor flips. We find new gauge invariance classes in theories with a nonlinearly realized scalar sector. In unitarity gauge, the same gauge invariance classes correspond to a decomposition of the scattering amplitude into pieces that satisfy the relevant Ward identities individually. In theories with a linearly realized scalar sector in $R_\xi$ gauge, no additional non-trivial gauge invariance classes exist compared to the unbroken case.
© Springer-Verlag, 2003
