Monte Carlo study of KDAR $\nu_{\mu}$ charged-current scattering on carbon

TL;DR

This study uses Monte Carlo simulations to analyze nuclear effects in KDAR muon neutrino interactions on carbon, highlighting the importance of FSI models and nucleon removal energy in energy reconstruction accuracy.

Contribution

It provides a comparative analysis of GENIE, NuWro, and GiBUU predictions for KDAR neutrino interactions, emphasizing the impact of nuclear and FSI models on missing energy reconstruction.

Findings

NuWro shows the best agreement with data among the generators.

Nuclear and FSI models significantly affect missing energy predictions.

Current models have limitations in the low-energy regime, indicating need for improvements.

Abstract

The neutrino energy reconstruction is crucial for reducing systematic uncertainties in neutrino oscillation experiments and improving cross-section measurements. Kaon-Decays-At-Rest (KDAR) neutrinos provide a unique opportunity to probe neutrino-nucleus interactions at low energies with a precisely known energy of 235.5 MeV. This work presents Monte Carlo predictions of missing energy due to nuclear effects in the KDAR $\nu_\mu$ charged-current scattering on the carbon nucleus for JSNS$^2$. The predictions from GENIE, NuWro, and GiBUU show a significant impact of nuclear and final state interaction (FSI) models, as well as nucleon removal energy, on missing energy reconstruction. Tuning the hA FSI model improves the predictions from GENIE. It is also observed that the nucleon elastic component of FSI leads to better predictions in NuWro compared to GENIE. NuWro shows the best agreement with data among the generators considered; however, the observed discrepancies with data across all generators highlight the limitations of current theoretical descriptions in the low-energy regime and the need for improvements in Monte Carlo modeling.