Chasing the light sterile neutrino: status of the STEREO experiment

Abstract

This article describes the status of the STEREO experiment. STEREO is a short-baseline reactor antineutrino experiment, whose primary goal is to study oscillations involving extra sterile neutrino states with Δm2 ∼ 0.1 − 1 eV, an hypothesis suggested by existing anomalies. Such hypothesis is tested by comparing antineutrino spectra in 6 identical cells located at a increasing distance from the reactor core of the ILL facility. Calibration sources have been used to characterise the detector response, perform energy reconstruction, and study the detection efficiency. Results of these studies, along with preliminary antineutrino and background rates, are reported here. STEREO has started operating in November 2016 and will collect data for 8 reactor cycles. Preliminary results based on 1.5 reactor cycles and ongoing analysis, which are mentioned here, will be released in early 2018.