Atmospheric neutrinos with the first detection units of KM3NeT/ARCA

Abstract

The KM3NeT Collaboration is constructing two deep-sea Cherenkov detectors in the Mediterranean Sea, aiming at neutrino oscillation measurements with the ORCA array, while the ARCA array aims at neutrino astronomy in the TeV range. In April 2021, 5 additional detection units were deployed in the ARCA site. The KM3NeT/ARCA instrumented volume is currently similar to the one of the ANTARES neutrino telescope. In this contribution, an analysis of the data obtained with the detector before April 2021 is presented as well as the analysis of the very first data from the new KM3NeT/ARCA configuration. The performance is demonstrated using atmospheric muons and the first atmospheric neutrinos are shown.