Precision measurements on $\delta_\text{CP}$ in MOMENT

TL;DR

This paper evaluates the potential of the MOMENT experiment to precisely measure the CP-violating phase in neutrino oscillations, comparing it with other experiments and identifying key factors affecting measurement accuracy.

Contribution

It provides a detailed analysis of how experimental parameters influence CP phase measurement precision and suggests optimal configurations and combinations of experiments for improved results.

Findings

Combining MOMENT, DUNE, and T2HK achieves δ_CP precision of 12° or better.

Systematic uncertainties and beam polarity fractions significantly impact measurement accuracy.

Adjusting baseline length to oscillation maxima enhances δ_CP measurement precision.

Abstract

As it is very promising to expect a discovery of CP violation in the leptonic sector, the precision measurement of the Dirac CP phase $\delta_\text{CP}$ is going to be one of the key interests in the future neutrino oscillation experiments. In this work, we examine the physics reach of the proposed medium baseline muon decay experiment MOMENT. In order to identify potential bottlenecks and opportunities to improve CP precision in MOMENT, we investigate the effect of statistical error, systematic uncertainties, fraction of the muon beam polarity, and adjusting the baseline length to match the first or second oscillation maximum on the precision measurement of $\delta_\text{CP}$. We also simulate superbeam experiments T2K, NO$\nu$A, T2HK, DUNE and T2HKK in comparison and complementary to MOMENT. To reach the precision of $\delta_\text{CP}$ at 12$^\circ$ or better at 1$\sigma$ confidence level, we find it sufficient to combine the data of MOMENT, DUNE and T2HK.