Combining $\nu_e$ Appearance and $\nu_\mu$ Disappearance Channels in Light Sterile Neutrino Oscillation Searches at Fermilab's Short-Baseline Neutrino Facility

TL;DR

This paper predicts the sensitivity of Fermilab's Short-Baseline Neutrino program to sterile neutrino oscillations by combining electron neutrino appearance and muon neutrino disappearance data, including new parameter space insights.

Contribution

It introduces the first combined sensitivity analysis for $ u_e$ appearance and $ u_$ disappearance channels in a 3+1 sterile neutrino model at Fermilab.

Findings

Sensitivity predictions for mixing angles $ heta_{14}$ and $ heta_{24}$.

Combined channel analysis improves detection prospects.

Results align with existing Fermilab sensitivity estimates.

Abstract

Of late, a number of instances of neutrino flux anomalies observed at short-baselines have given traction to the hypothesis of adding new neutrino flavours to our Standard Model set, albeit ones not associated with a partnered lepton. Anomalies observed at LSND, MiniBooNE and at short distances from nuclear reactors have suggested the existence of sterile mass states with masses on the scale of $\sim1\text{eV}$, prompting further investigations. Subsequently, Fermilab is set to host a Short-Baseline Neutrino (SBN) oscillation program which will cross-check each of these anomalies by deploying three state-of-the-art liquid argon detectors along the Booster Neutrino Beamline. Through an event-by-event Monte Carlo simulation study, this document presents short-baseline oscillation sensitivity predictions for SBN on a purely statistical basis in the scope of a 3+1 sterile neutrino model approximated with a two flavour mixing basis. As a world's first, sensitivities in parameter space to 3+1 mixing angles $\theta_{14}$ and $\theta_{24}$ are presented, in addition to the sensitivities gained by combining $\nu_\mu$ disappearance and $\nu_e$ appearance channel data. Provided also are energy spectra and 3+1 oscillation parameter sensitivity predictions for these two individual channels. The results agreed with parameter space sensitivity predictions already conceived by Fermilab to a satisfactory degree.