ORCA: measuring the neutrino mass hierarchy with atmospheric neutrinos in the Mediterranean

Topical Research Meeting: Prospects in Neutrino Physics

Van Elewyck, Véronique^1

Laboratoire Astroparticule et Cosmologie (APC), Université Paris Diderot, CNRS/IN2P3, CEA/Irfu, Obs. de Paris, Sorbonne Paris Cité, France^1

关键词: Atmospheric neutrinos;    Base-line performance;    Cherenkov Detectors;    Electron channel;    Feasibility studies;    Matter effects;    Neutrino physics;    Neutrino telescopes;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/598/1/012033/pdf
DOI  :  10.1088/1742-6596/598/1/012033

来源: IOP

【 摘 要 】

Since the measurement of the mixing angle θ13, the determination of the neutrino mass hierarchy has become a central challenge of neutrino physics. Recent studies have pointed out that it could reveal itself in the atmospheric neutrino sector, where oscillations are affected by Earth matter effects. This contribution reports on the ORCA feasibility study for such a measurement with an underwater Cherenkov detector based on the technology developed for the KM3NeT neutrino telescope. The baseline performances are discussed for a reference detector with 50 instrumented lines. Preliminary projections, based on the muon channel only, indicate that a 3 - 5σ significance measurement is within reach of a detector with an exposure of the order of 20 Mton years. Further improvement is expected to come from the electron channel, which is currently under study.