January 31, 2015
Usually the Lagrangian of a model for massive vector bosons is derived in a geometric way by the Higgs mechanism. We investigate whether this geometric structure is maintained under the renormalization group (RG) flow. Using the framework of Epstein-Glaser renormalization, we find that the answer is 'no', if the renormalization mass scale(s) are chosen in a way corresponding to the minimal subtraction scheme. This result is derived for the $U(1)$-Higgs model to 1-loop order. On the other hand we give a model-independent proof that physical consistency, which is a weak form of BRST-invariance of the time-ordered products, is stable under the RG-flow.