Old and new physics interpretations of the NuTeV anomaly

Abstract

We discuss whether the NuTeV anomaly can be explained, compatibly with all other data, by QCD effects (maybe, if the strange sea is asymmetric, or there is a tiny violation of isospin), new physics in propagators or couplings of the vector bosons (not really), loops of supersymmetric particles (no), dimension six operators (yes, for one specific SU(2)L-invariant operator), leptoquarks (not in a minimal way), extra U(1) gauge bosons (maybe: an unmixed Z′ coupled to B - 3Lμ also increases the muon g - 2 by about 10-9 and gives a 'burst' to cosmic rays above the GZK cutoff). © SISSA/ISAS 2002.