Neutrino-Nucleus Interactions  (Back to Research)

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Electrons for Neutrinos (CLAS Data-Mining): Neutrino oscillations offer a viable path to search for new physics beyond the standard model. High precision measurements of neutrino oscillations are expected to determine oscillations parameters with un-precedented accuracy, which will be sensitive to leptonic CP violations, non-standard interactions, new particles and more. In accelerator-driven experiments, the extraction of neutrino mixing parameters from neutrino oscillation experiments relies on the proper reconstruction of the incident neutrino energy and knowledge of the neutrino-nucleus interaction cross-section for various nuclei over a wide incident neutrino energy range.

The incident neutrino energy is typically reconstructed from the measured kinematics of final-state particles produced from the neutrino interactions with a target nucleus. This procedure requires superb understanding of nuclear structure and neutrino interaction mechanisms. These heavily rely on theoretical calculations that, for the most part, have not been tested directly using known energy beams.

As neutrinos and electrons are both leptons, there are many commonalities between their interactions with nuclei. We are therefore using data from the Jefferson-Lab CLAS large acceptance spectrometer to study electron scattering from a variety of targets at a range of beam energies. This data is used to confront interaction models and develop improved neutrino interaction event selection and energy reconstruction techniques. These will inform neutrino oscillation and cross section experiments and help obtain a better understanding of their associated systematic uncertainties. This is a unique approach that will provide crucial input for the next generation high-precision neutrino experiments.

Neutrino-Induced Proton Knockout (MicroBooNE): The MicroBooNE experiment at Fermi-Lab uses a 170 ton liquid argon time-projection chamber (LArTPC) to measure low-energy neutrino-nucleus cross sections and search for new physics by investigating an anomalous excess of low-energy events observed in the previous MiniBooNE experiment. The improved final-state detection capabilities of the MicroBooNE experiment will allow high-precision extraction of semi-inclusive and exclusive proton knockout cross-section. The latter are needed to achieve complete understanding of neutrino-nucleus interactions at the precision required to extract the CP-violating phase in future experiments.

We are working on studying these interactions including identification of final state protons, selection of quasi-elastic enhanced 1-muon 1-proton events, extraction of cross-sections, and studies of initial neutrino energy reconstruction. As MicroBooNE is a pioneering experiment in a large series of LArTPC detectors, the methods we are developing here will be used in various followup experiments.

Neutrino-Nucleus Interaction Event Generators: To properly connect the electron and neutrino scattering measurements, we are also working on implementing more reliable effective nuclear models, such as the Correlated Fermi-Gas model, into neutrino-nucleus event generators and on updating the GENIE electron-scattering simulation mode to include radiative effects (also relevant for electron-neutrino oscillation analyses), new From-Factor parameterizations and more.