Invisible neutrino decays at the MOMENT experiment

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 andν µ 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.

Exploring invisible neutrino decay at ESSnuSB

“…Studies of invisible decay in the accelerator neutrino experiments T2K [9], NOνA [10], MINOS [11], DUNE [12], and MOMENT [13] can be found in refs. [14][15][16][17][18]. For the study of invisible neutrino decay in the ongoing atmospheric neutrino experiment Super-Kamiokande (SK) [19] and the future atmospheric neutrino experiment INO [20], see refs.…”

Relaxing cosmological neutrino mass bounds with unstable neutrinos

“…In particular, the combined analysis of Super-Kamiokande, K2K and MINOS data provides the bound: τ ν 3 /m ν 3 2.9 × 10 −10 s eV −1 [129]. Upcoming neutrino oscillation experiments as DUNE, JUNO or ORCA, are expected to slightly improve the present bound on τ ν 3 [133][134][135][136][137][138][139][140].…”

Precision measurements on δCP in MOMENT

“…MOMENT is proposed to use a novel approach to generate a very intensive beam of neutrinos and antineutrinos via the decay of positive and negative muons, which allows to survey neutrino oscillations in eight different channels. In the past, MOMENT and its physics potential have been studied in CP violation discovery [16,17], non-standard neutrino interactions [17,18] and invisible neutrino decays [19].…”