Non-Standard neutrino interactions and neutral gauge bosons

Abstract

We investigate Non-Standard Neutrino Interactions (NSI) arising from a flavorsensitive Z boson of a new U (1) symmetry. We compare the limits from neutrino oscillations, coherent elastic neutrino-nucleus scattering, and Z searches at different beam and collider experiments for a variety of straightforward anomaly-free U (1) models generated by linear combinations of B − L and lepton-family-number differences L α − L β . 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 Z-Z mixing gives vanishing NSI in long-baseline experiments if a direct coupling between the U (1) gauge boson and matter is absent. In contrast, 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) symmetry.

Searches for atmospheric long-lived particles

“…Regarding the B − L model with HNL, as in the previous cases we get a best fit to IC data away from zero and, in particular, for Br(V → N )g 2 B−L ∼ 10 −6 − 10 −5 and cτ N ∼ 10 −4 km. Unfortunately, the required value of g B−L is excluded by collider constraints [49,57,58] in this dark photon mass range and, at the same time, such as small cτ N for a HNL at m N = 0.35 GeV is at least one order of magnitude too small, assuming that the mixing is below the present constraints from direct searches of HNL [13].…”

Lattice QCD and neutrino-nucleus scattering

“…Although not crucial to neutrino oscillations, the same experiments study weak neutralcurrent interactions of the Z boson and, possibly, non-Standard bosons [88,89]. The corresponding Dirac and Pauli form factors can be obtained from the proton and neutron electromagnetic form factors and the strange-quark contribution (accessible in parity-violating elastic electron-scattering experiments [90]) as…”

Nonstandard neutrino interactions at COHERENT, DUNE, T2HK and LHC

“…Also, because scenarios involving L e are heavily constrained in the low-mass region by electron beam-dump experiments [15][16][17][18][19][20], we set Q e = 0 and only consider the less constrained eletrophobic NSI. For the sake of illustration, we take the following three cases for our benchmark studies [21]:…”