The SciBooNE and MiniBooNE collaborations report the results of a u_mu disappearance search in the Delta m^2 region of 0.5-40 eV^2. The neutrino rate as measured by the SciBooNE tracking detectors is used to constrain the rate at the MiniBooNE Cherenkov detector in the first joint analysis of data from both collaborations. Two separate analyses of the combined data samples set 90% confidence level (CL) limits on u_mu disappearance in the 0.5-40 eV^2 Delta m^2 region, with an improvement over previous experimental constraints between 10 and 30 eV^2.
The MiniBooNE and SciBooNE collaborations report the results of a joint search for short baseline disappearance of bar{{ u}_{mu}} at Fermilabs Booster Neutrino Beamline. The MiniBooNE Cherenkov detector and the SciBooNE tracking detector observe antineutrinos from the same beam, therefore the combined analysis of their datasets serves to partially constrain some of the flux and cross section uncertainties. Uncertainties in the { u}_{mu} background were constrained by neutrino flux and cross section measurements performed in both detectors. A likelihood ratio method was used to set a 90% confidence level upper limit on bar{{ u}_{mu}} disappearance that dramatically improves upon prior limits in the {Delta}m^2=0.1-100 eV^2 region.
The MiniBooNE Collaboration reports first results of a search for $ u_e$ appearance in a $ u_mu$ beam. With two largely independent analyses, we observe no significant excess of events above background for reconstructed neutrino energies above 475 MeV. The data are consistent with no oscillations within a two neutrino appearance-only oscillation model.
We report a search result for a light sterile neutrino oscillation with roughly 2200 live days of data in the RENO experiment. The search is performed by electron antineutrino ($overline{ u}_e$) disappearance taking place between six 2.8 GW$_{text{th}}$ reactors and two identical detectors located at 294 m (near) and 1383 m (far) from the center of reactor array. A spectral comparison between near and far detectors can explore reactor $overline{ u}_e$ oscillations to a light sterile neutrino. An observed spectral difference is found to be consistent with that of the three-flavor oscillation model. This yields limits on $sin^{2} 2theta_{14}$ in the $10^{-4} lesssim |Delta m_{41}^2| lesssim 0.5$ eV$^2$ region, free from reactor $overline{ u}_e$ flux and spectrum uncertainties. The RENO result provides the most stringent limits on sterile neutrino mixing at $|Delta m^2_{41}| lesssim 0.002$ eV$^2$ using the $overline{ u}_e$ disappearance channel.
The results of a 3+1 sterile neutrino search using eight years of data from the IceCube Neutrino Observatory are presented. A total of 305,735 muon neutrino events are analyzed in reconstructed energy-zenith space to test for signatures of a matter-enhanced oscillation that would occur given a sterile neutrino state with a mass-squared differences between 0.01,eV$^2$ and 100,eV$^2$. The best-fit point is found to be at $sin^2(2theta_{24})=0.10$ and $Delta m_{41}^2 = 4.5{rm eV}^2$, which is consistent with the no sterile neutrino hypothesis with a p-value of 8.0%.
This paper reviews the results of the LSND and MiniBooNE experiments. The primary goal of each experiment was to effect sensitive searches for neutrino oscillations in the mass region with $Delta m^2 sim 1$ eV$^2$. The two experiments are complementary, and so the comparison of results can bring additional information with respect to models with sterile neutrinos. Both experiments obtained evidence for $bar u_mu rightarrow bar u_e$ oscillations, and MiniBooNE also observed a $ u_mu rightarrow u_e$ excess. In this paper, we review the design, analysis, and results from these experiments. We then consider the results within the global context of sterile neutrino oscillation models. The final data sets require a more extended model than the simple single sterile neutrino model imagined at the time that LSND drew to a close and MiniBooNE began. We show that there are apparent incompatibilities between data sets in models with two sterile neutrinos. However, these incompatibilities may be explained with variations within the systematic error. Overall, models with two (or three) sterile neutrinos seem to succeed in fitting the global data, and they make interesting predictions for future experiments.