Effects of BSMs on $\theta_{23}$ determination

TL;DR

This paper assesses how future long baseline experiments can determine the octant of the neutrino mixing angle θ23, considering the effects of non-unitarity in neutrino mixing and presenting confidence level contours.

Contribution

It introduces a detailed analysis of octant determination prospects incorporating non-unitarity effects, with contour plots on the (θ23-45°, δ) plane.

Findings

Octant determination is feasible at various confidence levels.

Non-unitarity impacts the sensitivity of octant resolution.

Contour plots illustrate the true θ23 values for octant identification.

Abstract

We investigate the prospects for determining the octant of $\theta_{23}$ in the future long baseline oscillation experiments. We present our results as contour plots on the ($\theta_{23}-45^\circ$, $\delta$)--plane, where $\delta$ is the CP phase, showing the true values of $\theta_{23}$ for which the octant can be experimentally determined at 3$\,\sigma$, 2$\,\sigma$ and 1$\,\sigma$ confidence level, in particular, the impact of the non-unitarity of neutrino mixing.