The Physics of antineutrinos in DUNE and resolution of octant degeneracy

TL;DR

This paper investigates how the DUNE experiment can determine the octant of the leptonic mixing angle by analyzing neutrino and antineutrino oscillation probabilities, emphasizing the importance of antineutrino runs to resolve degeneracies.

Contribution

It demonstrates the role of antineutrino data in resolving octant degeneracy in DUNE, considering matter effects and combined run strategies.

Findings

Antineutrino runs enhance octant sensitivity.

Matter effects cause differences in neutrino and antineutrino probabilities.

Combined neutrino and antineutrino data can resolve degeneracies.

Abstract

We study the capability of the DUNE experiment, which will be the first beam based experiment with a wide band flux profile, to uncover the octant of the leptonic mixing angle $\theta_{23}$ (i.e., $\theta_{23}$ is $< 45^\circ$ or $>45^\circ$). In this work, we find that for the DUNE baseline of 1300 km, due to enhanced matter effect, the neutrino and antineutrino probabilities are different which creates a tension in the case of combined runs because of which octant sensitivity also can come from disappearance channel. In view of this, we study the physics of antineutrinos in DUNE and explore the role of antineutrinos run that is required to resolve the octant degeneracy at a certain confidence levels.