Probing invisible neutrino decay with KM3NeT-ORCA

TL;DR

This paper evaluates KM3NeT/ORCA's ability to detect invisible neutrino decay, finding it can set competitive limits and that decay has minimal impact on other oscillation parameter measurements.

Contribution

It introduces the sensitivity analysis of KM3NeT/ORCA to invisible neutrino decay and assesses its impact on standard oscillation measurements.

Findings

Sensitivity to decay parameter $1/\alpha_3 < 180$ ps/eV at 90% CL.

No significant effect of decay on measurements of $\theta_{23}$, $\Delta m^2_{31}$, and mass ordering.

Abstract

In the era of precision measurements of the neutrino oscillation parameters, upcoming neutrino experiments will also be sensitive to physics beyond the Standard Model. KM3NeT/ORCA is a neutrino detector optimised for measuring atmospheric neutrinos from a few GeV to around 100 GeV. In this paper, the sensitivity of the KM3NeT/ORCA detector to neutrino decay has been explored. A three-flavour neutrino oscillation scenario, where the third neutrino mass state $\nu_3$ decays into an invisible state, e.g. a sterile neutrino, is considered. We find that KM3NeT/ORCA would be sensitive to invisible neutrino decays with $1/\alpha_3=\tau_3/m_3 < 180$~$\mathrm{ps/eV}$ at $90\%$ confidence level, assuming true normal ordering. Finally, the impact of neutrino decay on the precision of KM3NeT/ORCA measurements for $\theta_{23}$, $\Delta m^2_{31}$ and mass ordering have been studied. No significant effect of neutrino decay on the sensitivity to these measurements has been found.