Unraveling neutrino parameters with a magical beta-beam experiment at INO

Abstract

We expound in detail the physics reaches of an experimental set-up in which the proposed large magnetized iron detector at the India-based Neutrino Observatory (INO) would serve as the far detector for a so-called beta-beam. If this pure ν_e and/or ν̅_e beam is shot from some source location like CERN such that the source-detector distance L⋍7500 km, the impact of the CP phase δ_CP on the oscillation probability and associated parameter correlation and degeneracies are almost negligible. This "magical" beta-beam experiment would have unprecedented sensitivity to the neutrino mass hierarchy and θ₁₃, two of the missing ingredients needed for our understanding of the neutrino sector. With Lorentz boost γ=650 and irrespective of the true value of δ_CP, the neutrino mass hierarchy could be determined at 3σ C.L. if sin²2θ₁₃(true)>5.6×10⁻⁴and we can expect an unambiguous signal for θ₁₃ at 3σ C.L if sin²2θ₁₃(true)>5.1×10⁻⁴independent of the true neutrino mass hierarchy.