Speaker
Description
One of the important unknowns in neutrino oscillation physics is the
the leptonic CP phase $\delta_{CP}$. Because of ambiguity between $\delta_{CP}$ and neutrino mass hierarchy, experiments have to be designed in such a way as to measure these parameters independent of each other. Long baseline experiments like DUNE is exclusively designed to measure $\delta_{CP}$ in regions without hierarchy ambiguity and atmospheric neutrino experiments like INO are designed to measure hierarchy without $\delta_{CP}$ ambiguity. However atmospheric neutrinos are not usually used to probe $\delta_{CP}$. Here we present the study that, at sub GeV energies atmospheric neutrinos can be used to probe $\delta_{CP}$ irrespective of mass hierarchy. We show that when the events are binned as a function of $(E_l,\cos\theta_l)$, the energy and direction of the final state leptons,a consistent distinction between various $\delta_{CP}$ values is obtained. Since there is no sensitivity to the mass ordering/hierarchy, $\delta_{CP}$ can be measured without hierarchy ambiguity at these energies. A $\chi^2$ analysis assuming a generic detector with perfect resolutions and efficiencies, and which can separate charged current $\nu_e,\overline{\nu}_e,\nu_\mu$ and $\overline{\nu}_\mu$ events will also be discussed.
| Working Group | WG1 : Neutrino Oscillation Physics |
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