Invisible neutrino decays at the MOMENT experiment

Abstract

Abstract We investigate invisible decays of the third neutrino mass eigenstate in future accelerator neutrino experiments using muon-decay beams such as MuOn-decay MEdium baseline NeuTrino beam experiment (MOMENT). MOMENT has outstanding potential to measure the deficit or excess in the spectra caused by neutrino decays, especially in ν μ and ν ¯ μ $$ {\overline{\nu}}_{\mu } $$ disappearance channels. Such an experiment will improve the constraints of the neutrino lifetime τ 3. Compared with exclusion limits in the current accelerator neutrino experiments T2K and NOvA under the stable ν assumption, we expect that MOMENT gives the bound of τ 3 /m 3 ≥ 10−11 s/eV at 3σ, which is better than their recent limits: τ 3 /m 3 ≥ 7 × 10−13 s/eV in NOvA and τ 3 /m 3 ≥ 1.41 × 10−12 s/eV in T2K. The non-decay scenario is expected to be excluded by MOMENT at a confidence level > 3σ, if the best fit results in T2K and NOvA are confirmed. We further find that reducing systematic uncertainties is more important than the running time. Finally, we find some impact of τ 3 /m 3 on the precision measurement of other oscillation parameters.

Keywords

• Beyond Standard Model
• Neutrino Physics