Prospects of measuring $\sin^2 2Θ_{13}$ and the sign of $Δm^2$ with a massive magnetized detector for atmospheric neutrinos

Abstract

The pattern of oscillation parameters emerging from current experimental data can be further elucidated by the observation of matter effects. In contrast to planned experiments with conventional neutrino beams, atmospheric neutrinos offer the possibility to search for Earth-induced matter effects with very long baselines. Resonant matter effects are asymmetric on neutrinos and anti-neutrinos, depending on the sign of $Δm^2$. In a three-generation oscillation scenario, this gives access to the mass hierarchy of neutrinos, while the size of the asymmetry would measure the admixture of electron neutrinos to muon/tau neutrino oscillations (the mixing angle $Θ_{13}$). The sensitivity to these effects is discussed after the detailed simulation of a realistic experiment based on a massive detector for atmospheric neutrinos with charge identification. We show how a detector, which measure and distinguish between $ν_μ$ and $\barν_μ$ charged current events, might be sensitive to matter effects using atmospheric neutrinos, provided the mixing angle $Θ_{13}$ is large enough.