Neutrino parameters with magical beta-beam at INO

Abstract

We have studied the physics reach of an experiment where neutrinos produced in a beta-beam facility at CERN are observed in a large magnetized iron calorimeter (ICAL) at the India-based Neutrino Observatory (INO). The idea of beta-beam is based on the production of a pure, intense, collimated beam of electron neutrinos or their antiparticles via the beta decay of accelerated radioactive ions circulating in a storage ring. Interestingly, the CERN-INO distance of 7152 km happens to be tantalizingly close to the so-called 'magic' baseline where the sensitivity to the neutrino mass ordering (sign of Δm²₃₁≡m²₃-m²₁) and more importantly, θ₁₃, goes up significantly, while the sensitivity to the unknown CP phase is absent. This permits such an experiment involving the golden P_eμ channel to make precise measurements of the mixing angle θ₁₃ and neutrino mass hierarchy avoiding the issues of intrinsic degeneracies and correlations which plague other baselines.