MiniBooNE and MicroBooNE Combined Fit to a 3+1 Sterile Neutrino Scenario

Area of Science:

• Particle Physics
• Neutrino Physics
• Experimental Physics

Background:

• The standard model of particle physics includes three active neutrinos.
• Anomalies in neutrino oscillation experiments suggest the possibility of additional, non-interacting sterile neutrinos.
• The MiniBooNE and MicroBooNE experiments investigate neutrino oscillations at short baselines.

Purpose of the Study:

• To test the "3+1" sterile neutrino model using MiniBooNE and MicroBooNE experimental data.
• To determine the best-fit parameters for the sterile neutrino model.
• To compare the "3+1" model's explanatory power against the standard three-neutrino model.

Main Methods:

• Performed a "3+1" neutrino oscillation fit to MiniBooNE electron and muon (anti)neutrino data.
• Combined MiniBooNE data with electron neutrino data from the MicroBooNE experiment.
• Utilized exclusive and inclusive charged-current quasielastic analyses for fitting.

Main Results:

• The "3+1" model provided a significantly better fit to the data compared to the no-oscillation scenario.
• Best-fit parameters for the sterile neutrino model were determined, including mass-squared difference and mixing parameters.
• A statistical preference for the "3+1" model was found at 4.3σ (or 3.4σ for inclusive analysis).

Conclusions:

• The experimental results support the existence of a light sterile neutrino.
• The "3+1" model successfully explains observed electron neutrino appearance and muon neutrino disappearance.
• Further investigation with combined datasets strengthens the evidence for sterile neutrinos.