Cosmic ray tagging in Icarus: a combined analysis

The Short Baseline Neutrino (SBN) program at Fermilab aims to explore significant regions of neutrino oscillation parameter space, allowing to search for sterile neutrinos at the eV mass scale, as suggested by existing experimental anomalies. For this purpose, two Liquid Argon Time Projection Chambers – Lar TPC- are located along the Booster Neutrino Beamline to study both electron neutrino appearance and muon neutrino disappearance. ICARUS is the farthest of these detectors, located at a shallow depth, 600 m from the neutrino source. It is surrounded by a Cosmic Ray Tagger system to mitigate the impact of cosmic ray background. On average ~ 11 muon tracks are expected to cross the detector during the ~ 1 ms drift time. The cosmic ray tagger is composed of plastic scintillator bars. It tags cosmic muons by measuring their position and crossing time. By combining information from the three ICARUS subdetector, the cosmic ray tagger the photon detection system and the TPC data, it is possible to classify and reject cosmic particles recorded both during and outside the beam spill. In this work, a multivariate analysis is developed and discussed, along with the implementation of a novel matching algorithm that accurately assign a time to each track reconstructed in the Time Projection Chamber using the photon detection system and Cosmic Ray tagger. This analysis reaches a tagging efficiency of TPC reconstructed tracks over 90%.