Non-Standard neutrino interactions and neutral gauge bosons

Abstract

We investigate Non-Standard Neutrino Interactions (NSI) arising from a flavor-sensitive Z'Z′ boson of a new U(1)'U(1)′ symmetry. We compare the limits from neutrino oscillations, coherent elastic neutrino–nucleus scattering, and Z'Z′ searches at different beam and collider experiments for a variety of straightforward anomaly-free U(1)'U(1)′ models generated by linear combinations of B-LB−L and lepton-family-number differences L_\alpha-L_\betaLα−Lβ. Depending on the flavor structure of those models it is easily possible to avoid NSI signals in long-baseline neutrino oscillation experiments or change the relative importance of the various experimental searches. We also point out that kinetic ZZ–Z'Z′ mixing gives vanishing NSI in long-baseline experiments if a direct coupling between the U(1)'U(1)′ gauge boson and matter is absent. In contrast, ZZ–Z'Z′ mass mixing generates such NSI, which in turn means that there is a Higgs multiplet charged under both the Standard Model and the new U(1)'U(1)′ symmetry.