# The 21st International Workshop on Neutrinos from Accelerators (NUFACT2019)

25-31 August 2019
The Grand Hotel Daegu
Asia/Seoul timezone

## Hierarchy independent sensitivity to leptonic $\delta_{CP}$ with low energy atmospheric neutrinos

26 Aug 2019, 19:00
2h 30m
Dynasty Hall (2F) (The Grand Hotel Daegu)

### Dynasty Hall (2F)

#### The Grand Hotel Daegu

Board: 33
Poster Presentation

### Speaker

Dr Lakshmi S Mohan (Dept. of Physics, Indian Institute of Technology Madras)

### 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

### Primary authors

Prof. Indumathi D (The Institute of Mathematical Sciences, Chennai ) Dr Lakshmi S Mohan (Dept. of Physics, Indian Institute of Technology Madras) Prof. Murthy M. V. N (The Institute of Mathematical Sciences, Chennai)

### Presentation Materials

There are no materials yet.