Simulation Study on neutrino nucleus cross section measurement in Segmented Detector at Spallation Neutron Source

TL;DR

This simulation study assesses how a segmented detector at the Spallation Neutron Source measures neutrino-electron cross sections, focusing on energy reconstruction challenges due to scattering and showers, and explores spectrum unfolding feasibility.

Contribution

It introduces a simulation framework to evaluate energy spectrum distortion and unfolding in segmented detectors for neutrino interactions with Fe and Pb.

Findings

Energy spectrum distortion increases with atomic number.

Unfolding methods can recover the original spectrum under certain conditions.

Statistical accuracy estimates for neutrino energy measurement are provided.

Abstract

Knowledge of $\nu_e$-$\mathrm{Fe}/\mathrm{Pb}$ differential cross sections for $\nu_e$ energy below several tens of MeV scale is believed to be crucial in understanding Supernova physics. In a segmented detector at Spallation Neutrino Source, $\nu_e$ energy reconstructed from the electron range measurement is strongly affected because of both multiple scattering and electromagnetic showers occurring along the electron passage in target materials. In order to estimate the effect, a simulation study has been performed with a cube block model assuming a perfect tracking precision. The distortion of energy spectrum is observed to be proportional to the atomic number of target material. Feasibility of unfolding the distorted $\nu_e$ energy spectrum is studied for both Fe and Pb cases. Evaluation of statistical accuracy attainable is therefore provided for a segmented detector.