Prospects of measuring the leptonicCPphase with atmospheric neutrinos

Abstract

We have studied the prospects of measuring the $CP$ violating phase with atmospheric neutrinos at a large magnetized iron calorimeter detector considering the muons (directly measurable) of the neutrino events generated by a Monte Carlo event generator Nuance. The effect of ${\ensuremath{\theta}}_{13}$ and ${\ensuremath{\delta}}_{CP}$ appears dominantly neither in atmospheric neutrino oscillation nor in solar neutrino oscillation, but appears as subleading in both cases. These are observable in the range of $E\ensuremath{\sim}1\text{ }\text{ }\mathrm{GeV}$ for atmospheric neutrino, where solar and atmospheric oscillation couple. In this regime, the quasielastic events dominate and the energy resolution is very good, but the angular resolution is very poor. Unlike beam experiments this poor angular resolution acts against its measurements. However, we find that one can be able to distinguish ${\ensuremath{\delta}}_{CP}\ensuremath{\approx}0\ifmmode^\circ\else\textdegree\fi{}$ and 180\ifmmode^\circ\else\textdegree\fi{} at 90% confidence level. We find no significant sensitivity for ${\ensuremath{\delta}}_{CP}\ensuremath{\approx}90\ifmmode^\circ\else\textdegree\fi{}$ or 270\ifmmode^\circ\else\textdegree\fi{}.