Fig. 3: Constraints on parameters of the 4ν oscillation model.
From: Search for light sterile neutrinos with two neutrino beams at MicroBooNE
a,b, The red lines show exclusion limits at the 95% CLs level in the plane of \(\Delta {m}_{41}^{2}\) and \({\sin }^{2}(2{\theta }_{{\rm{\mu }}{\rm{e}}})\) (a) or \({\sin }^{2}(2{\theta }_{{\rm{e}}{\rm{e}}})\) (b). All the regions to the right of these lines are excluded by the MicroBooNE data. In a, the yellow shaded area is the LSND 99% CL allowed regions3, which neglects the degeneracy between νe disappearance and appearance. The light blue area is the MiniBooNE 95% CL allowed region58, considering both νe disappearance and appearance. In b, the purple shaded area is the 2σ allowed region of the gallium anomaly59. The dark blue shaded area is the 2σ allowed region from the Neutrino-4 experiment9. For context, note that the stronger-than-expected constraint on \({\sin }^{2}(2{\theta }_{{\rm{\mu e}}})\), driven by the deficit observed in the BNB νe CC FC sample and the excess in the NuMI νμ CC sample, is discussed in detail in the Methods and Extended Data Fig. 2.
