Demonstration of MeV-Scale Physics in Liquid Argon Time Projection Chambers Using ArgoNeuT

TL;DR

This paper demonstrates the successful detection and reconstruction of MeV-scale energy depositions in a liquid argon TPC, crucial for future neutrino and supernova studies, using data from the ArgoNeuT detector at Fermilab.

Contribution

It provides the first experimental evidence of MeV-scale physics in a LArTPC, validating simulation models and reconstruction techniques for low-energy neutrino interactions.

Findings

Measured energy depositions are consistent with photon emissions from nuclear de-excitation.

Reconstructed depositions match FLUKA Monte Carlo simulations.

Demonstrates LArTPC capability for supernova neutrino detection.

Abstract

MeV-scale energy depositions by low-energy photons produced in neutrino-argon interactions have been identified and reconstructed in ArgoNeuT liquid argon time projection chamber (LArTPC) data. ArgoNeuT data collected on the NuMI beam at Fermilab were analyzed to select isolated low-energy depositions in the TPC volume. The total number, reconstructed energies and positions of these depositions have been compared to those from simulations of neutrino-argon interactions using the FLUKA Monte Carlo generator. Measured features are consistent with energy depositions from photons produced by de-excitation of the neutrino's target nucleus and by inelastic scattering of primary neutrons produced by neutrino-argon interactions. This study represents a successful reconstruction of physics at the MeV-scale in a LArTPC, a capability of crucial importance for detection and reconstruction of supernova and solar neutrino interactions in future large LArTPCs.