Very-short-baseline electron neutrino disappearance

We consider possible indications of very-short-baseline (VSBL) electron neutrino disappearance into sterile neutrinos in MiniBooNE neutrino data and Gallium radioactive source experiments. We discuss the compatibility of such a disappearance with reactor and MiniBooNE antineutrino data. We find a tension between neutrino and antineutrino data which could be due to: (1) statistical fluctuations; (2) underestimate of systematic uncertainties; (3) exclusion of our hypothesis of very-short-baseline nu(e) disappearance; (4) a violation of CPT symmetry. Considering the first possibility, we present the results of a combined fit of all data, which indicate that P(nu e)->nu(e)< 1 with 97.04% CL. We consider also the possibility of CPT violation, which leads to the best-fit value A(ee)(CPT,bf)=-0.17 for the asymmetry of the nu(e) and nu(e) survival probabilities and A(ee)(CPT)< 0 at 99.71% CL.