Status of the BEST sterile neutrino search

The Baksan Experiment on Sterile Transitions (BEST) searches for the neutrino oscillation to ~1 eV sterile neutrino by exploring the Gallium anomaly. Based on the Gallium-Germanium neutrino telescope (GGNT) of the SAGE experiment, the BEST setup is comprised of two concentric zones of liquid Ga target to explore the neutrino oscillation on the meter scale. Any deficit in the neutrino capture rates in the inner and the outer zones, as well as their differences, is sensitive to the existence of neutrino oscillation to a sterile state at a short baseline. 

Since July 5^th to Oct. 23^rd 2019, the two-zone target was exposed to the mono-energetic ⁵¹Cr source 10 independent times with 20 ⁷¹Ge extractions from the two Ga targets. The ⁷¹Ge decay rates were measured from July 2019 to March 2020 to determine the total production rate from the neutrino source. In this talk, we present the status of the BEST experiment. The experimental details and the systematics considerations are also reported.