First Observation of Low Energy Electron Neutrinos in a Liquid Argon Time Projection Chamber

TL;DR

This paper reports the first experimental observation of low energy electron neutrinos in a liquid argon TPC, demonstrating its capabilities for neutrino detection and background rejection in relevant energy ranges.

Contribution

It presents the first observation of electron neutrinos in a liquid argon TPC and introduces methods for separating electrons from gamma backgrounds.

Findings

37 electron candidate events identified

80% purity of electron selection achieved

Effective separation of electrons from gamma backgrounds

Abstract

The capabilities of liquid argon time projection chambers (LArTPCs) to reconstruct the spatial and calorimetric information of neutrino events have made them the detectors of choice in a number of experiments, specifically those looking to observe electron neutrino ($\nu_e$) appearance. The LArTPC promises excellent background rejection capabilities, especially in this "golden" channel for both short and long baseline neutrino oscillation experiments. We present the first experimental observation of electron neutrinos and anti-neutrinos in the ArgoNeut LArTPC, in the energy range relevant to DUNE and the Fermilab Short Baseline Neutrino Program. We have selected 37 electron candidate events and 274 gamma candidate events, and measured an 80\% purity of electrons based on a topological selection. Additionally, we present a of separation of electrons from gammas using calorimetric energy deposition, demonstrating further separation of electrons from background gammas.