Experimental parameters for a Cerium 144 based intense electron antineutrino generator experiment at very short baselines

Abstract

The standard three-neutrino oscillation paradigm, associated with small squared mass splittings $\mathrm{\ensuremath{\Delta}}{m}^{2}\ensuremath{\ll}0.1\text{ }\text{ }{\mathrm{eV}}^{2}$, has been successfully built up over the last 15 years using solar, atmospheric, long baseline accelerator and reactor neutrino experiments. However, this well-established picture might suffer from anomalous results reported at very short baselines in some of these experiments. If not experimental artifacts, such results could possibly be interpreted as the existence of at least an additional fourth sterile neutrino species, mixing with the known active flavors with an associated mass splitting $\mathrm{\ensuremath{\Delta}}{m}_{\text{new}}^{2}\ensuremath{\gg}0.01\text{ }\text{ }{\mathrm{eV}}^{2}$ and being insensitive to standard weak interactions. Precision measurements at very short baselines (5--15 m) with intense MeV ${\overline{\ensuremath{\nu}}}_{e}$ emitters can be used to probe these anomalies. In this article, the expected ${\overline{\ensuremath{\nu}}}_{e}$ signal and backgrounds of a generic experiment which consists of deploying an intense ${\ensuremath{\beta}}^{\ensuremath{-}}$ radioactive source inside or in the vicinity of a large liquid scintillator detector are studied. The technical challenges to perform such an experiment are identified, along with quantifying the possible source- and detector-induced systematics and their impact on the sensitivity to the observation of neutrino oscillations at short baselines.