Higgs-free Massive Nonabelian Gauge Theories

Abstract

We analyze nonabelian massive Higgs-free theories in the causal Epstein-Glaser approach. Recently, there has been renewed interest in these models. In particular we consider the well-known Curci-Ferrari model and the nonabelian Stückelberg models. We explicitly show the reason why the considered models fail to be unitary. In our approach only the asymptotic (linear) BRS-symmetry has to be considered.

Comments: 13 pages, latex, no figures, published version, some misprints corrected and a few comments added