Search for anomalies in the {\nu}e appearance from a {\nu}{\mu} beam

TL;DR

This study from the ICARUS experiment investigates neutrino oscillations from muon neutrinos to electron neutrinos over a long baseline, finding results consistent with standard expectations and setting new limits on anomalous oscillation probabilities.

Contribution

The paper provides an updated analysis with nearly double the data, improving sensitivity to neutrino oscillation anomalies and confirming previous findings with enhanced statistical power.

Findings

Observed 4 { u}e events against an expectation of 6.4 ± 0.9.

Limits on oscillated events are set at 3.7 and 8.3 for 90% and 99% confidence levels.

Oscillation probability limits are 3.4 x 10^-3 and 7.6 x 10^-3 respectively.

Abstract

We report an updated result from the ICARUS experiment on the search for {\nu}{\mu} ->{\nu}e anomalies with the CNGS beam, produced at CERN with an average energy of 20 GeV and travelling 730 km to the Gran Sasso Laboratory. The present analysis is based on a total sample of 1995 events of CNGS neutrino interactions, which corresponds to an almost doubled sample with respect to the previously published result. Four clear {\nu}e events have been visually identified over the full sample, compared with an expectation of 6.4 +- 0.9 events from conventional sources. The result is compatible with the absence of additional anomalous contributions. At 90% and 99% confidence levels the limits to possible oscillated events are 3.7 and 8.3 respectively. The corresponding limit to oscillation probability becomes consequently 3.4 x 10-3 and 7.6 x 10-3 respectively. The present result confirms, with an improved sensitivity, the early result already published by the ICARUS collaboration.