Cosmic Ray Background Rejection with Wire-Cell LArTPC Event Reconstruction in the MicroBooNE Detector

TL;DR

This paper presents a new Wire-Cell 3D event reconstruction method for liquid argon TPCs that significantly improves cosmic ray background rejection and neutrino event selection efficiency in surface-based neutrino experiments.

Contribution

The paper introduces a novel Wire-Cell 3D reconstruction technique that enhances cosmic background rejection and neutrino event identification in LArTPC detectors.

Findings

Cosmic contamination reduced to 14.9% for high-energy events.

Neutrino selection efficiency is over 80% for muon and electron neutrinos.

Performance surpasses previous algorithms, aiding neutrino oscillation research.

Abstract

For a large liquid argon time projection chamber (LArTPC) operating on or near the Earth's surface to detect neutrino interactions, the rejection of cosmogenic background is a critical and challenging task because of the large cosmic ray flux and the long drift time of the TPC. We introduce a superior cosmic background rejection procedure based on the Wire-Cell three-dimensional (3D) event reconstruction for LArTPCs. From an initial 1:20,000 neutrino to cosmic-ray background ratio, we demonstrate these tools on data from the MicroBooNE experiment and create a high performance generic neutrino event selection with a cosmic contamination of 14.9\% (9.7\%) for a visible energy region greater than O(200)~MeV. The neutrino interaction selection efficiency is 80.4\% and 87.6\% for inclusive $\nu_\mu$ charged-current and $\nu_e$ charged-current interactions, respectively. This significantly improved performance compared to existing reconstruction algorithms, marks a major milestone toward reaching the scientific goals of LArTPC neutrino oscillation experiments operating near the Earth's surface.