Sensitivity of octant of $\theta_{23}$, CP violation and mass hierarchy in NO$\nu$A with multinucleon and detector effects

TL;DR

This study assesses how nuclear effects and detector performance influence the sensitivity of NOνA to key neutrino oscillation parameters, finding that comprehensive modeling and improved detectors enhance measurement precision.

Contribution

It introduces a detailed nuclear model including multinucleon effects and detector effects, demonstrating their impact on neutrino parameter sensitivity analysis in NOνA.

Findings

Comprehensive nuclear modeling significantly improves sensitivity.

Higher octant of θ23 and normal hierarchy enhance detection precision.

Enhanced detector performance further improves measurement accuracy.

Abstract

In this work, we investigate how multinucleon enhancement and RPA (Random Phase Approximation) suppression can affect the measurement of three unknown neutrino oscillation parameters - the CP-violating phase $\delta_{CP}$, the octant of the atmospheric mixing angle $\theta_{23}$, and the determination of the mass hierarchy, in the appearance channel of the NO$\nu$A experiment. We include the presence of the detector effect as well in the analysis, which is crucial for capturing realistic experimental scenarios. We also conducted a comparison between the nuclear model Effective Spectral Function (calculated within the RFG model) with and without Transverse Enhancement in terms of sensitivity analysis. It is found that the analysis using our comprehensive model QE(+RPA)+2p2h along with Effective Spectral Function+Transverse Enhancement exhibits significantly enhanced sensitivity compared to the pure QE interaction process, in all the cases.Also, the higher octant of $\theta_{23}$, the lower half plane of $\delta_{CP}$, and the normal mass hierarchy (HO-LHP-NH) exhibit improved sensitivity, enabling a more precise determination of the corresponding parameters. Furthermore, it is also noted that improving the performance of the detector also improves the results. Thus, including multinucleon effects and improving detector efficiency have the potential to enhance the capabilities of the NO$\nu$A (and other long baseline) experiment in conducting precise parameter studies.