Reactor antineutrino oscillations and gadolinium loaded Super-Kamiokande detector

Abstract

We explore the potential of measuring the solar neutrino oscillation parameters in the proposed gadolinium loaded Super-Kamiokande (SK-Gd) detector. Gadolinium dissolved in water can detect neutrons much more efficiently than pure water. This imparts the detector the ability to observe electron type antineutrinos, transforming Super-Kamiokande into a huge reactor antineutrino detector with an event rate approximately 43 times higher than that observed in KamLAND. We simulate the reactor antineutrino data expected in this high statistics detector. We use these prospective data to study the precision with which the solar neutrino oscillation parameters, Δm2⊙ and sin2θ⊙, can be determined (i) with the SK-Gd detector, and (ii) by combining the SK-Gd data with the global data on solar neutrino oscillations. For comparison and completeness the allowed regions of Δm2⊙ and sin2θ⊙, expected to be obtained from the data of the solar neutrino and KamLAND experiments, are also presented. We find that the SK-Gd experiment could provide one of the most precise (if not the most precise) determination of the solar neutrino oscillation parameters Δm2⊙ and sin2θ⊙.