Exploring atmospheric neutrino oscillations at ESSnuSB

TL;DR

This paper analyzes atmospheric neutrino oscillations at the ESSnuSB facility, demonstrating the potential to determine neutrino mass ordering and $ heta_{23}$ octant with high confidence over a decade of data collection.

Contribution

It provides the first detailed sensitivity analysis of atmospheric neutrino oscillations at ESSnuSB, highlighting its capability to resolve mass ordering and $ heta_{23}$ octant.

Findings

Mass ordering can be resolved at 3σ after 4 years and 5σ after 10 years.

Wrong $ heta_{23}$ octant can be excluded at 3σ after 4 years for normal ordering.

Results are complementary to the accelerator neutrino program.

Abstract

This study provides an analysis of atmospheric neutrino oscillations at the ESSnuSB far detector facility. The prospects of the two cylindrical Water Cherenkov detectors with a total fiducial mass of 540 kt are investigated over 10 years of data taking in the standard three-flavor oscillation scenario. We present the confidence intervals for the determination of mass ordering, $\theta_{23}$ octant as well as for the precisions on $\sin^2\theta_{23}$ and $|\Delta m_{31}^2|$. It is shown that mass ordering can be resolved by $3\sigma$ CL ($5\sigma$ CL) after 4 years (10 years) regardless of the true neutrino mass ordering. Correspondingly, the wrong $\theta_{23}$ octant could be excluded by $3\sigma$ CL after 4 years (8 years) in the case where the true neutrino mass ordering is normal ordering (inverted ordering). The results presented in this work are complementary to the accelerator neutrino program in the ESSnuSB project.