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Olivier, Andrew

Publications and source records attributed to Olivier, Andrew.

6 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Measuring the Multi-Neutron Antineutrino Cross Section at Low Charged Hadron Energy in MINERvA

Current and future accelerator neutrino oscillation experiments need neutrino interaction models with smaller systematic uncertainties to resolve much of delta CP phase space. Final state interactions (FSI) and scattering off of correlated nuclei (2p2h) are poorly understood processes that currently contribute large uncertainties to leading models. These processes have proven difficult to study because they often produce relatively low energy nucleons. Protons up to about 100 MeV are below the detection threshold of some accelerator neutrino detectors, and neutrons are usually discounted as undetectable. This poster presents a measurement of the multi-neutron antineutrino cross section at low available energy using the MINERvA detector at Fermilab. This interaction channel is particularly sensitive to FSI and 2p2h interactions. A sideband-driven background constraint that greatly reduces uncertainties on the result will be presented. The measured cross section is compared to GENIE v3 models with different FSI treatments and the SuSA model's 2p2h predictions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Neutrons in MINERvA and the Antineutrino Multi-Neutron Production Cross Section

Neutrinos are among a handful of particles in the Standard Model of particle physics whose properties have not yet been fully measured. Neutrino oscillations, discovered in the late 1990s, still have yet to be fully characterized. Early evidence suggests that neutrinos and antineutrinos may undergo neutrino oscillations differently. So, multiple collaborations are building and operating kTon-scale particle detectors to try to measure this CP violation in the neutrino sector of the Standard Model. Measuring neutrino and antineutrino energies is essential to characterizing oscillation phenomena. But neutrons interfere with (anti)neutrino energy measurements because they are hard to detect in (anti)neutrino detectors. Furthermore, there are very few measurements of neutrons produced by (anti)neutrinos in the energy range of interest to accelerator-based oscillation experiments. The MINERvA collaboration initially tried to fill this gap by measuring the rate of neutron-induced activity i n plastic. The data deviated significantly from leading model predictions, but it could not be determined which models needed to be tuned. MINERvA’s first neutron counting result also cannot be compared to future models because it was not suitable for unsmearing. This thesis first expands upon MINERvA’s first foray into neutron detection at higher antineutrino energy. Neutron detection efficiency is enhanced by advances in analysis algorithms. Then, an unsmeared cross section for producing two or more neutrons is measured. Existing antineutrino interaction models again over-predict the rate of neutron production by antineutrinos. Preliminary neutron production rate measurements in MINERvA’s iron and lead targets suggest that models are also over-predicting neutron production in heavier nuclei.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Measurement of the π - -Ar total hadronic cross section at the LArIAT experiment

We present the first measurement of the negative pion total hadronic cross section on argon in a restricted phase space, which we performed at the Liquid Argon In A Testbeam (LArIAT) experiment. All hadronic reaction channels, as well as hadronic elastic interactions with scattering angle greater than 5° are included. The pions have kinetic energies in the range 100–700 MeV and are produced by a beam of charged particles impinging on a solid target at the Fermilab test beam facility. LArIAT employs a 0.24 ton active mass liquid argon time projection chamber (LArTPC) to measure the pion hadronic interactions. For this measurement, LArIAT has developed the “thin slice method,” a new technique to measure cross sections with LArTPCs. While moderately higher, our measurement of the π - -Ar total hadronic cross section is generally in agreement with the geant4 prediction.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2020

The Liquid Argon In A Testbeam (LArIAT) Experiment

The LArIAT liquid argon time projection chamber, placed in a tertiary beam of charged particles at the Fermilab Test Beam Facility, has collected large samples of pions, muons, electrons, protons, and kaons in the momentum range 0∼30–0140 MeV/c. This paper describes the main aspects of the detector and beamline, and also reports on calibrations performed for the detector and beamline components.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗