[Paper Review] Measurement of the Electron-Neutrino Charged-Current Inclusive Cross- Section on Argon in MicroBooNE

P. Abratenko|arXiv (Cornell University)|Apr 7, 2021

Neutrino Physics Research32 references32 citations

TL;DR

This paper presents the first measurement of the flux-averaged charged-current inclusive cross section for electron neutrinos and antineutrinos on argon using the MicroBooNE liquid argon time projection chamber (LArTPC). Using 2.4×10²⁰ protons on target, it observes 80 νₑ + ν̄ₑ events, measures a cross section of 6.84 ±1.51 (stat.) ±2.33 (syst.)×10⁻³⁹ cm²/nucleon for Eν > 250 MeV, and demonstrates a fully automated dE/dx-based electron/photon discrimination technique in a surface LArTPC, validating its use for future short-baseline neutrino experiments.

ABSTRACT

<strong>Parallel Flash Talk</strong> at the<br> "XIX International Workshop on Neutrino Telescopes"<br> on line - 18-26 February, 2021

Motivation & Objective

• To measure the flux-averaged charged-current inclusive cross section for electron neutrinos and antineutrinos on argon using a liquid argon time projection chamber.
• To demonstrate a fully automated dE/dx-based particle identification technique for distinguishing electron and photon showers in a surface LArTPC.
• To provide a high-precision, direct measurement of νₑ interactions on argon to reduce uncertainties in neutrino oscillation analyses.
• To validate the feasibility of electron neutrino reconstruction in surface LArTPC detectors despite cosmic ray backgrounds.
• To support the Short-Baseline Neutrino (SBN) Program at Fermilab by improving the understanding of electron neutrino interactions in argon.

Proposed method

• The measurement uses data from the MicroBooNE detector exposed to the off-axis NuMI beam, with an integrated exposure of 2.4×10²⁰ protons on target.
• Reconstructed νₑ + ν̄ₑ interactions are identified via charged-current events with final-state electrons or photons, using a combination of vertex reconstruction and shower topology.
• A fully automated dE/dx-based particle discrimination method is applied to distinguish electrons from photons based on energy deposition per unit path length and distance from the interaction vertex.
• The analysis applies a kinematic threshold of 48 MeV/c for final-state electron momentum and includes all angular phases of the electron.
• Backgrounds from cosmic rays and misidentified photons are suppressed using detailed simulation and data-driven calibration, including cosmic ray tagging and laser calibration.
• Cross section is extracted using a binned maximum-likelihood fit to the reconstructed energy spectrum, with flux and detector response modeled using GENIE and NuWro simulations.

Experimental results

Research questions

• RQ1 What is the flux-averaged charged-current inclusive cross section for electron neutrinos and antineutrinos on argon in the energy range above 250 MeV?
• RQ2 Can a fully automated dE/dx-based technique reliably distinguish electron and photon showers in a surface LArTPC under cosmic ray backgrounds?
• RQ3 How does the measured νₑ + ν̄ₑ cross section compare to theoretical predictions from GENIE and NuWro?
• RQ4 What is the effective number of νₑ + ν̄ₑ events observed in argon, and how does this compare to previous measurements?
• RQ5 To what extent can electron neutrino interactions be reconstructed in a surface LArTPC with realistic background conditions?

Key findings

• The flux-averaged charged-current inclusive cross section for νₑ + ν̄ₑ on argon is measured to be 6.84 ±1.51 (stat.) ±2.33 (syst.)×10⁻³⁹ cm²/nucleon for neutrino energies above 250 MeV.
• A total of 80 νₑ + ν̄ₑ events were observed, representing the largest such sample to date in argon.
• The measurement demonstrates the first fully automated application of a dE/dx-based particle discrimination technique for electron and photon showers in a LArTPC neutrino detector.
• The result is in good agreement with theoretical predictions from both GENIE and NuWro event generators.
• The analysis successfully reconstructs electron neutrino interactions in a surface LArTPC despite significant cosmic ray backgrounds, validating its feasibility for future experiments.
• The measurement provides a critical input for short-baseline neutrino oscillation experiments, reducing uncertainties in νₑ flux and cross section modeling.