Implications of a new light gauge boson for neutrino physics

Abstract

We study the impact of light gauge bosons on neutrino physics. We show that they can explain the NuTeV anomaly and also escape the constraints from neutrino experiments if they are very weakly coupled and have a mass of a few GeV. Lighter gauge bosons with stronger couplings could explain both the NuTeV anomaly and the positive anomalous magnetic moment of the muon. However, in the simple model we consider in this paper (say a purely vectorial extra U(1) current), they appear to be in conflict with the precise measurements of \nu-e elastic scattering cross sections. The surprising agreement that we obtain between our naive model and the NuTeV anomaly for a Z' mass of a few GeV may be a coincidence. However, we think it is interesting enough to deserve attention and perhaps a more careful analysis, especially since a new light gauge boson is a very important ingredient for the Light Dark Matter scenario.Comment: 9 page

Curtailing the dark side in non-standard neutrino interactions

“…An alternative, studied in some detail in Refs. [34][35][36][37][38], is to assume that the neutrino NSI are generated by new physics well below the EW scale. For example, renormalizable, gauge-invariant models leading to large NSI have been constructed considering a Z boson associated to a new U (1) X symmetry, where X is a certain combination of lepton or baryon numbers.…”

Light weakly coupled axial forces: models, constraints, and projections

“…If SM particles are singlets under the corresponding U (1) D (D for "dark") group, the leading SM interaction with the new gauge boson arises through kinetic mixing with the hypercharge field strength tensor, such that the associated dark gauge boson A couples predominantly to the electromagnetic current after electroweak symmetry breaking (EWSB) [1,2]. Alternatively, if U (1) D gauges a subset of SM quantum numbers, the new gauge boson couples directly to a current of SM fields, which can radiatively induce a nonzero kinetic mixing as well; popular examples include the anomaly-free combinations B − L [3][4][5], L i − L j [6,7], B − 3L i [8], and B − L + xY [9], where x ∈ R. These abelian extensions are ubiquitous in the model-building literature and regularly invoked to explain anomalies in dark matter detection [10][11][12] and resolve discrepancies in precision physics measurements [13,14], to name only a few applications. However, these extensions typically induce sizable A interactions only with vector currents of SM fermions, which limits their applicability in phenomenological settings that also require axial couplings (e.g.…”

Constraints on nonstandard intermediate boson exchange models from neutrino-electron scattering

“…From the best fit, (h ee ) 4 = [1.10 ± 4.07 ± 3.65] × 10 −22 (22) is obtained at χ 2 /dof = 8.8/9 with its corresponding upper limit at 90% C.L. of h ee < 5.63 × 10 −6 (23) for TEXONO. Similarly, for LSND, from the best fit, (h ee ) 4 = [6.59 ± 11.51 ± 9.35] × 10 −20 (24) is obtained at χ 2 /dof = 10.3/13 with its corresponding upper limit at 90% C.L.…”

“…The NLS1B is one of the examples of such kinds of particles. A spin-1 particle could also be involved in explaining the NuTeV anomaly [23]. In addition to this, the NLS1B may also explain the muon anomalous magnetic moment value [24].…”