Constraining sterile neutrinos by core-collapse supernovae with multiple detectors

TL;DR

This paper demonstrates that future supernova neutrino detectors can robustly exclude the existence of eV-scale sterile neutrinos within 10 kpc, providing constraints far surpassing current cosmological and experimental limits.

Contribution

It provides a novel method to test sterile neutrino hypotheses using supernova neutrino signals during the neutronization burst phase.

Findings

Supernova neutrino detection can exclude sterile neutrinos at >99% confidence within 10 kpc.

Constraints on sterile neutrino mixing parameters are over two orders of magnitude better than current bounds.

Future detectors like DUNE, Hyper-K, and JUNO are effective in probing sterile neutrino models.

Abstract

The eV-scale sterile neutrino has been proposed to explain some anomalous results in experiments, \textit{such as} the deficit of reactor neutrino fluxes and the excess of $\bar{\nu}_\mu\to\bar{\nu}_e$ in LSND. This hypothesis can be tested by future core-collapse supernova neutrino detection independently since the active-sterile mixing scheme affects the flavor conversion of neutrinos inside the supernova. In this work, we compute the predicted supernova neutrino events in future detectors -- DUNE, Hyper-K, and JUNO -- for neutrinos emitted during the neutronization burst phase when the luminosity of $\nu_e$ dominates the other flavors. We find that for a supernova occurring within 10 kpc, the difference in the event numbers with and without sterile neutrinos allows to exclude the sterile neutrino hypothesis at more than $99\%$ confidence level robustly. The derived constraints on sterile neutrinos mixing parameters are comparably better than the results from cosmology and on-going or proposed reactor experiments by more than two orders of magnitude in the $\sin^22\theta_{14}$-$\Delta m_{41}^2$ plane.