Optimizing the ${\theta }_{23}$ octant search in long baseline neutrino experiments

Abstract

We study the possibility of determining the octant of the neutrino mixing angle ${\theta }_{23}$, that is, whether ${\theta }_{23}>45^{\circ }$ or ${\theta }_{23}<45^{\circ }$, in long baseline neutrino experiments. Here we numerically derived the sensitivity limits within which these experiments can determine, by measuring the probability of the ${\nu }_{\mu }\to {\nu }_e$ transitions, the octant of ${\theta }_{23}$ with a $5\sigma$ certainty. The interference of the CP violation angle $\delta$ with these limits, as well as the effects of the baseline length and the run-time ratio of neutrino and antineutrino modes of the beam have been analyzed.

Comments: 16 pages, 4 figures