Neutrino-nucleus scattering reexamined: Quasielastic scattering and pion production entanglement and implications for neutrino energy reconstruction

TL;DR

This paper uses the GiBUU model to analyze how misidentification of quasielastic and pion production events affects neutrino energy reconstruction in long-baseline experiments, highlighting the importance of accurate event classification.

Contribution

It provides a detailed assessment of event misidentification rates and their dependence on detection thresholds, improving understanding of neutrino energy reconstruction accuracy.

Findings

20% of quasielastic events are misidentified in current experiments.

Over 40% of 1pi+ events are misidentified as CCQE due to pion absorption.

Final-state interactions significantly influence neutrino energy reconstruction.

Abstract

We apply the GiBUU model to questions relevant for current and future neutrino long-baseline experiments, we address in particular the relevance of charged-current reactions for neutrino disappearance experiments. A correct identification of charged-current quasielastic (CCQE) events - which is the signal channel in oscillation experiments - is relevant for the neutrino energy reconstruction and thus for the oscillation result. We show that about 20% of the quasielastic cross section is misidentified in present-day experiments and has to be corrected for by means of event generators. Furthermore, we show that also a significant part of 1pi+ (> 40%) events is misidentified as CCQE mainly caused by the pion absorption in the nucleus. We also discuss the dependence of both of these numbers on experimental detection thresholds. We further investigate the influence of final-state interactions on the neutrino energy reconstruction.