Entanglement of Quasielastic Scattering and Pion Production

TL;DR

Accurately reconstructing neutrino energy is challenging due to the entanglement of quasielastic scattering and pion production, leading to significant uncertainties impacting neutrino oscillation measurements.

Contribution

This paper highlights the impact of process entanglement on energy reconstruction and quantifies the resulting uncertainties in neutrino experiments like MiniBooNE and T2K.

Findings

Fermi motion causes at least 15% uncertainty in energy reconstruction.

Entanglement of scattering processes increases errors beyond Fermi motion effects.

Calculated misidentification cross section for electron appearance due to neutral pions.

Abstract

The extraction of neutrino oscillation parameters requires the determination of the neutrino energy from observations of the hadronic final state. Here we discuss the difficulties connected with this energy reconstruction for the ongoing experiments MiniBooNE and T2K. We point out that a lower limit to the uncertainty in the reconstructed energy from Fermi motion alone amounts to about 15%. The entanglement of very different elementary processes, in this case quasielastic scattering and pion production, in the actual observables leads to considerably larger errors. We discuss the sensitivity of the energy reconstruction to detection techniques and experimental acceptances. We also calculate the misidentification cross section for electron appearance in the T2K experiment due to neutral pion production.