Probing Neutrino Parameters with a Two-Baseline Beta-Beam Set-up

Abstract

We discuss the prospects of exploring the neutrino mass parameters with a CERN based Betabeam experiment using two different detectors at two different baselines. The proposed set-up consists of a 50 kton iron calorimeter (ICAL) at a baseline of around 7150 km which is roughly the magic baseline, e.g., ICAL@INO, and a 50 kton Totally Active Scintillator Detector at a distance of 730 km, e.g., at Gran Sasso. We take 8 B and 8 Li source ions with a boost factor γ of 650 for the magic baseline while for the closer detector we consider 18 Ne and 6 He ions with a range of Lorentz boosts. We find that the locations of the two d etectors complement each other leading to an exceptional high sensitivity. With γ = 650 for 8 B/ 8 Li and γ = 575 for 18 Ne/ 6 He and total luminosity corresponding to 5 × (1.1 × 10 19 ) and 5 × (2.9 × 10 19 ) useful ion decays in neutrino and antineutrino modes respectively, we find tha t the two-detector set-up can probe maximal CP violation and establish the neutrino mass ordering if sin 2 2θ13 is 1.8 × 10 −5 and 4.6 × 10 −5 , respectively, or more. The sensitivity reach for sin 2 2θ13 itself is 5.3 × 10 −5 . CP violation can be discovered for 64% of the possible δCP values for sin 2 2θ13 ≥ 8 × 10 −5 .