BEST potential in testing the eV-scale sterile neutrino explanation of
  reactor antineutrino anomalies
  Baksan Experiment on Sterile Neutrino (BEST) is presently at the stage of
production of the artificial neutrino source Cr-51, the gallium exposure will
start in July and proceed for three months. While aiming specifically at
investigating the Gallium neutrino anomaly (SAGE and GALLEX experiments), BEST
can do more and it is tempting to estimate its ability in testing sterile
neutrino explanation of antineutrino (reactor) anomalies. We observe a moderate
sensitivity to the region in model parameter space (sterile neutrino mass and
mixing with active electron neutrino) outlined by the old reactor antineutrino
anomaly and the best fit of DANSS experiment, while the Neutrino-4 favorite
region falls right in the BEST ballpark. In particular, by analyzing
SAGE+GALLEX and Neutrino-4 $\chi^2$ distributions we find that Neutrino-4
results are fully consistent with the Gallium anomaly, the significance of the
combined anomaly almost reaches 4$\sigma$ level. If the BEST confirms the
Neutrino-4 results, the joint analysis will indicate more than 5$\sigma$
evidence for the sterile neutrino of eV-scale mass.
