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 νₑ 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_νₑ→νₑ<1 with 97.04% CL. We consider also the possibility of $CPT$ violation, which leads to the best-fit value AₑₑCPT,bf=-0.17 for the asymmetry of the νₑ and νₑ survival probabilities and AₑₑCPT<0 at 99.71% CL.