Improved Constraints on Sterile Neutrino Mixing from Disappearance Searches in the MINOS, MINOS+, Daya Bay, and Bugey-3 Experiments

Abstract

Searches for electron antineutrino, muon neutrino, and muon antineutrino disappearance driven by sterile neutrino mixing have been carried out by the Daya Bay and MINOS+ collaborations. This Letter presents the combined results of these searches, along with exclusion results from the Bugey-3 reactor experiment, framed in a minimally extended four-neutrino scenario. Significantly improved constraints on the \(\theta_{\mu e}\) mixing angle are derived that constitute the most stringent limits to date over five orders of magnitude in the sterile mass-squared splitting \(\Delta m^2_{41}\), excluding the 90\% C.L. sterile-neutrino parameter space allowed by the LSND and MiniBooNE observations at 90\%~CL\(_s\) for \(\Delta m^2_{41}<5\,\)eV\(^2\).Furthermore, the LSND and MiniBooNE 99\%~C.L. allowed regions are excluded at 99\%~CL\(_s\) for \(\Delta m^2_{41}\)~\(<\)~1.2 eV\(^2\).