Implications of MicroBooNE's low sensitivity to electron antineutrino interactions in the search for the MiniBooNE excess

Abstract

The MicroBooNE experiment searched for an excess of electron-neutrinos in the Booster Neutrino Beam (BNB), providing direct constraints on νe-interpretations of the MiniBooNE low-energy excess (LEE). In this article, we show that if the MiniBooNE LEE is caused instead by an excess of ν¯e, then liquid argon detectors, such as MicroBooNE, SBND, and ICARUS, would have poor sensitivity to it. This is due to a strong suppression of ν¯e-Ar40 cross sections in the low-energy region of the excess. The MicroBooNE results are consistent at the 2σ CL with a scenario in which the MiniBooNE excess is sourced entirely by ν¯e interactions. The opportune location of ANNIE, a Gd-loaded water Cherenkov detector, allows for a direct search for a ν¯e flux excess in the BNB using inverse beta-decay events.