Prospects for measuring the neutrino mass hierarchy with KM3NeT/ORCA

Abstract: ORCA (Oscillation Research with Cosmics in the Abyss) is the low-energy branch of KM3NeT, the next-generation research infrastructure hosting underwater Cherenkov detectors in the Mediterranean Sea. ORCA's primary goal is the determination of the neutrino mass hierarchy by measuring the matter-induced modifications on the oscillation probabilities of few-GeV atmospheric neutrinos. The ORCA detector design foresees a dense configuration of KM3NeT neutrino detection technology, optimised for measuring the interactions of neutrinos in the energy range of 3 - 20 GeV. To be deployed at the French KM3NeT site, ORCA's multi-PMT optical modules will exploit the excellent optical properties of deep-sea water to accurately reconstruct both shower-like (mostly electron neutrino) and track-like (mostly muon neutrino) events in order to collect a high-statistics sample of few-GeV neutrino events. This contribution reviews the methods and technology of the ORCA detector, and discusses the prospects for measuring the neutrino mass hierarchy as well as the potential to improve the measurement precision on other oscillation parameters.