Neutrino energy reconstruction problems and neutrino oscillations

TL;DR

This paper examines the limitations of neutrino energy reconstruction methods based on quasielastic kinematics, highlighting the impact of multinucleon interactions on energy estimates and implications for neutrino oscillation experiments.

Contribution

It introduces a probabilistic approach to neutrino energy reconstruction that accounts for multinucleon effects, improving accuracy in oscillation analyses.

Findings

Multinucleon interactions cause significant deviations in energy reconstruction.

Reshaping of energy distributions affects interpretation of experimental data.

The method provides a more accurate true neutrino energy distribution from reconstructed data.

Abstract

We discuss the accuracy of the usual procedure for neutrino energy reconstruction which is based on the quasielastic kinematics. Our results are described in terms of a probability distribution for a real neutrino energy value. Several factors are responsible of the deviations from the reconstructed value. The main one is the multinucleon component of the neutrino interaction which in the case of Cherenkov detectors enters as a quasielastic cross section, increasing the mean neutrino energy which can differ appreciably from the reconstructed value. As an application we derive, for excess electron events attributed to the conversion of muon neutrinos, the true neutrino energy distribution based on the experimental one which is given in terms of the reconstructed value. The result is a reshaping effect. For MiniBooNE the low energy peak is suppressed and shifted at higher energies, which may influence the interpretation in terms of oscillation. For T2K at the Super Kamiokande far detector the reshaping translates into a narrowing of the energy distribution.