Active to sterile neutrino mixing limits from neutral-current   interactions in MINOS
  Results are reported from a search for active to sterile neutrino oscillations in the MINOS long-baseline experiment, based on the observation of neutral-current neutrino interactions, from an exposure to the NuMI neutrino beam of $7.07\times10^{20}$ protons on target. A total of 802 neutral-current event candidates is observed in the Far Detector, compared to an expected number of $754\pm28\rm{(stat.)}\pm{37}\rm{(syst.)}$ for oscillations among three active flavors. The fraction $f_s$ of disappearing \numu that may transition to $\nu_s$ is found to be less than 22% at the 90% C.L. 
MINOS Collaboration: P. Adamson, D. J. Auty, D. S. Ayres, C.   Backhouse, G. Barr, M. Bishai, A. Blake, G. J. Bock, D. J. Bo...
hep-ex