Letter of Intent for KM3NeT 2.0

TL;DR

The paper outlines the plan for KM3NeT 2.0, a deep-sea neutrino telescope network in the Mediterranean aimed at discovering high-energy neutrino sources and determining neutrino mass hierarchy, building on recent astrophysical and particle physics discoveries.

Contribution

It proposes a phased, multi-site infrastructure with innovative detector configurations to enhance neutrino detection and analysis capabilities, advancing the field of neutrino astronomy and physics.

Findings

Design of a multi-site deep-sea neutrino telescope network

Implementation plan for phased deployment and resource optimization

Expected improved resolution and complementary detection methods

Abstract

The main objectives of the KM3NeT Collaboration are i) the discovery and subsequent observation of high-energy neutrino sources in the Universe and ii) the determination of the mass hierarchy of neutrinos. These objectives are strongly motivated by two recent important discoveries, namely: 1) The high-energy astrophysical neutrino signal reported by IceCube and 2) the sizable contribution of electron neutrinos to the third neutrino mass eigenstate as reported by Daya Bay, Reno and others. To meet these objectives, the KM3NeT Collaboration plans to build a new Research Infrastructure consisting of a network of deep-sea neutrino telescopes in the Mediterranean Sea. A phased and distributed implementation is pursued which maximises the access to regional funds, the availability of human resources and the synergetic opportunities for the earth and sea sciences community. Three suitable deep-sea sites are identified, namely off-shore Toulon (France), Capo Passero (Italy) and Pylos (Greece). The infrastructure will consist of three so-called building blocks. A building block comprises 115 strings, each string comprises 18 optical modules and each optical module comprises 31 photo-multiplier tubes. Each building block thus constitutes a 3-dimensional array of photo sensors that can be used to detect the Cherenkov light produced by relativistic particles emerging from neutrino interactions. Two building blocks will be configured to fully explore the IceCube signal with different methodology, improved resolution and complementary field of view, including the Galactic plane. One building block will be configured to precisely measure atmospheric neutrino oscillations.