First search for sterile neutrino oscillation leading to $\nu_{\mu}$ disappearance in the Booster Neutrino Beam at ICARUS

TL;DR

This paper reports the first search for sterile neutrino oscillations causing muon neutrino disappearance using the ICARUS detector at Fermilab's Booster Neutrino Beam, finding no significant evidence but setting exclusion limits.

Contribution

It presents the first oscillation analysis by ICARUS with BNB data, establishing a methodology and initial constraints on sterile neutrino parameters.

Findings

No statistically significant muon neutrino disappearance observed.

Exclusion contours set in the sterile neutrino parameter space.

Analysis is currently systematics limited due to flux and interaction uncertainties.

Abstract

We present a search for muon neutrino disappearance in the Booster Neutrino Beam (BNB) at Fermilab using the ICARUS detector. Neutrino interactions identified as muon neutrinos interacting with argon nuclei via the charged current interaction and having only a muon and at least one proton in the final state (1$\mu$Np) have been selected from data collected in 2022-2023 (ICARUS Run 2) and compared with a simulation-based expectation. In the context of a fit to a two-neutrino approximation of the sterile 3+1 model, including the impact of systematic uncertainty from the flux, neutrino interaction, and detector models, we find no statistically significant muon neutrino disappearance at the ICARUS baseline of 600 meters from the BNB target. Corresponding 90% C.L. exclusion contours in $\Delta m^2_{41}$ - sin$^22\theta_{\mu\mu}$ space are presented. This is the first oscillation analysis produced by ICARUS exposed to the BNB. We note that the analysis is systematics limited due to large unconstrained uncertainties from the flux and interaction models. In future joint analyses, data from ICARUS and the SBND detector, exposed to the BNB at 110 meters from target, will be combined to provide significant constraint of these uncertainties, enabling a robust, world-leading two-detector analysis.