Some conclusive considerations on the comparison of the ICARUS nu_mu to nu_e oscillation search with the MiniBooNE low-energy event excess

TL;DR

The ICARUS experiment conducted a sensitive search for muon-to-electron neutrino oscillations and found no evidence of excess events, challenging the MiniBooNE low-energy anomaly and suggesting it may be due to instrumental effects.

Contribution

This study provides new limits on neutrino oscillation probabilities and compares ICARUS data with MiniBooNE results, highlighting a persistent tension and questioning the origin of the MiniBooNE excess.

Findings

ICARUS sets limits of 3.4E-3 and 7.6E-3 on oscillation probability at 90% and 99% CL.

The tension between ICARUS limits and MiniBooNE excess is confirmed at 90% CL.

MiniBooNE low-energy excess may be due to instrumental effects or unknown phenomena.

Abstract

A sensitive search for anomalous LSND-like nu_mu to nu_e oscillations has been performed by the ICARUS Collaboration exposing the T600 LAr-TPC to the CERN to Gran Sasso (CNGS) neutrino beam. The result is compatible with the absence of additional anomalous contributions giving a limit to oscillation probability of 3.4E-3 and 7.6E-3 at 90% and 99% confidence levels respectively showing a tension between these new limits and the low-energy event excess (200 < E_nu QE < 475 MeV) reported by MiniBooNE Collaboration. A more detailed comparison of the ICARUS data with the MiniBooNE low-energy excess has been performed, including the energy resolution as obtained from the official MiniBooNE data release. As a result the previously reported tension is confirmed at 90% C.L., suggesting an unexplained nature or an otherwise instrumental effect for the MiniBooNE low energy event excess