Search for sterile neutrinos in MINOS and MINOS+ using a two-detector fit

TL;DR

This study searched for sterile neutrinos by analyzing muon neutrino disappearance in two detectors over long baselines, finding no evidence but setting the most stringent limits to date on certain mixing parameters.

Contribution

It provides the first combined MINOS and MINOS+ analysis searching for sterile neutrinos with a two-detector fit, setting new limits on mixing parameters.

Findings

No evidence for sterile neutrino mixing was observed.

Set the most stringent limits on $ heta_{24}$ for $ riangle m^2_{41} > 10^{-4}$ eV$^2$.

Used a combined fit to energy spectra in two detectors.

Abstract

A search for mixing between active neutrinos and light sterile neutrinos has been performed by looking for muon neutrino disappearance in two detectors at baselines of 1.04 km and 735 km, using a combined MINOS and MINOS+ exposure of $16.36\times10^{20}$ protons-on-target. A simultaneous fit to the charged-current muon neutrino and neutral-current neutrino energy spectra in the two detectors yields no evidence for sterile neutrino mixing using a 3+1 model. The most stringent limit to date is set on the mixing parameter $\sin^2\theta_{24}$ for most values of the sterile neutrino mass-splitting $\Delta m^2_{41} > 10^{-4}$ eV$^2$.