The ORCA Option for KM3NeT

TL;DR

This paper discusses the feasibility of determining the neutrino mass hierarchy using atmospheric neutrino oscillation patterns detected by the KM3NeT deep-sea telescope, highlighting physics, signatures, and simulation insights.

Contribution

It introduces the ORCA project as a novel approach to measure neutrino mass hierarchy with deep-sea detector technology and provides preliminary sensitivity estimates.

Findings

Preliminary sensitivity suggests at least 20 Mton-years exposure needed.

Simulation studies indicate feasibility of hierarchy determination.

Physics signatures of atmospheric neutrino oscillations are analyzed.

Abstract

It has recently been suggested that the neutrino mass hierarchy can be experimentally determined from the oscillation pattern of atmospheric neutrinos passing through the Earth by measuring the two-dimensional arrival pattern of neutrinos in energy and zenith angle, in the energy regime of about 3-20 GeV. ORCA (Oscillation Research with Cosmics in the Abyss) is a study addressing the feasibility of such a measurement employing the deep-sea neutrino telescope technology developed for the KM3NeT project. In the following, the underlying physics and resulting experimental signatures will be discussed and some aspects of the ongoing simulation studies presented. A preliminary sensitivity estimate derived from a simplified study strongly indicates that an exposure of at least 20 Mton-years will be required to arrive at conclusive results.