papers

Publications (77)

hep-ex2025

The ANTARES detector: two decades of neutrino searches in the Mediterranean Sea

A. Albert, S. Alves, M. André +138

Interest for studying cosmic neutrinos using deep-sea detectors has increase after the discovery of a diffuse flux of cosmic neutrinos by the IceCube collaboration and the possibil…

astro-ph.HE2026

Combined KM3NeT/ARCA and ANTARES search for compact neutrino sources

V. Kulikovskiy, B. Caiffi, S. Alves Garre +9

The paper presents a joint search for point-like high‑energy neutrino sources by combining data from the ANTARES and KM3NeT/ARCA detectors using a binned likelihood analysis.

#neutrino astronomy#point source search#combined detector analysis#KM3NeT
astro-ph.HE2022

Limits on the nuclearite flux using the ANTARES neutrino telescope

ANTARES Collaboration, A. Albert, S. Alves +143

In this work, a search for nuclearites of strange quark matter by using nine years of ANTARES data taken in the period 2009-2017 is presented. The passage through matter of these p…

hep-ex2025

Study of tau neutrinos and non-unitary neutrino mixing with the first six detection units of KM3NeT/ORCA

KM3NeT Collaboration, S. Aiello, A. Albert +274

Oscillations of atmospheric muon and electron neutrinos produce tau neutrinos with energies in the GeV range, which can be observed by the ORCA detector of the KM3NeT neutrino tele…

hep-ex2026

Atmospheric neutrino constraints on Lorentz invariance violation with the first six detection units of KM3NeT/ORCA

KM3NeT Collaboration, O. Adriani, A. Albert +294

Lorentz invariance is a fundamental symmetry underlying both the Standard Model of particle physics and General Relativity. Testing its validity provides a direct means of searchin…

hep-ex2025

Search for an eV-scale sterile neutrino with the first six detection units of KM3NeT/ORCA

KM3NeT Collaboration, O. Adriani, A. Albert +285

The existence of an eV-scale sterile neutrino has been proposed to explain several anomalous experimental results obtained over the course of the past 25 years. The first search fo…

astro-ph.HE2021

Search for neutrinos from the tidal disruption events AT2019dsg and AT2019fdr with the ANTARES telescope

ANTARES Collaboration, A. Albert, S. Alves +141

On October 1, 2019, the IceCube Collaboration detected a muon track neutrino with high probability of being of astrophysical origin, IC191001A. After a few hours, the tidal disrupt…

astro-ph.IM2025

The Online Data Filter for the KM3NeT Neutrino Telescopes

O. Adriani, S. Aiello, A. Albert +279

The KM3NeT research infrastructure comprises two neutrino telescopes located in the deep waters of the Mediterranean Sea, namely ORCA and ARCA. KM3NeT/ORCA is designed for the meas…

astro-ph.HE2022

Search for solar atmospheric neutrinos with the ANTARES neutrino telescope

ANTARES Collaboration, A. Albert, S. Alves +145

Solar Atmospheric Neutrinos (SAs) are produced by the interaction of cosmic rays with the solar medium. The detection of SAs would provide useful information on the composi…

astro-ph.HE2020

ANTARES search for point-sources of neutrinos using astrophysical catalogs: a likelihood stacking analysis

A. Albert, M. André, M. Anghinolfi +136

A search for astrophysical point-like neutrino sources using the data collected by the ANTARES detector between January 29, 2007 and December 31, 2017 is presented. A likelihood st…

hep-ex2025

gSeaGen code by KM3NeT: an efficient tool to propagate muons simulated with CORSIKA

S. Aiello, A. Albert, A. R. Alhebsi +260

The KM3NeT Collaboration has tackled a common challenge faced by the astroparticle physics community, namely adapting the experiment-specific simulation software to work with the C…

astro-ph.HE2022

Search for Spatial Correlations of Neutrinos with Ultra-High-Energy Cosmic Rays

The ANTARES collaboration, A. Albert, S. Alves +1042

For several decades, the origin of ultra-high-energy cosmic rays (UHECRs) has been an unsolved question of high-energy astrophysics. One approach for solving this puzzle is to corr…

hep-ex2021

Measurement of the atmospheric and energy spectra with the ANTARES neutrino telescope

A. Albert, S. Alves, M. André +139

This letter presents a combined measurement of the energy spectra of atmospheric and in the energy range between 100 GeV and 50 TeV with the ANTARES neut…

astro-ph.IM2025

Acoustic Positioning for Deep Sea Neutrino Telescopes with a System of Piezo Sensors Integrated into Glass Spheres

A. Albert, S. Alves, M. André +137

Position calibration in the deep sea is typically done by means of acoustic multilateration using three or more acoustic emitters installed at known positions. Rather than using hy…

astro-ph.HE2025

KM3NeT Constraint on Lorentz-Violating Superluminal Neutrino Velocity

KM3NeT Collaboration, O. Adriani, S. Aiello +290

Lorentz invariance is a fundamental symmetry of spacetime and foundational to modern physics. One of its most important consequences is the constancy of the speed of light. This in…

astro-ph.HE2024

Results of the follow-up of ANTARES neutrino alerts

A. Albert, S. Alves, M. André +188

High-energy neutrinos could be produced in the interaction of charged cosmic rays with matter or radiation surrounding astrophysical sources. To look for transient sources associat…

hep-ex2021

Atmospheric neutrinos with the first detection units of KM3NeT/ARCA

A. Sinopoulou, R. Coniglione, R. Muller +1

The KM3NeT Collaboration is constructing two deep-sea Cherenkov detectors in the Mediterranean Sea. The ARCA detector aims at TeV-PeV neutrino astronomy, while the ORCA detector is…

astro-ph.HE2021

The KM3NeT potential for the next core-collapse supernova observation with neutrinos

KM3NeT Collaboration, S. Aiello, A. Albert +245

The KM3NeT research infrastructure is under construction in the Mediterranean Sea. It consists of two water Cherenkov neutrino detectors, ARCA and ORCA, aimed at neutrino astrophys…

astro-ph.HE2020

Observation of the cosmic ray shadow of the Sun with the ANTARES neutrino telescope

ANTARES Collaboration, A. Albert, M. André +134

The ANTARES detector is an undersea neutrino telescope in the Mediterranean Sea. The search for point-like neutrino sources is one of the main goals of the ANTARES telescope, requi…

astro-ph.SR2009

The size distribution of magnetic bright points derived from Hinode/SOT observations

D. Utz, A. Hanslmeier, C. Möstl +3

Context. Magnetic Bright Points (MBPs) are small-scale magnetic features in the solar photosphere. They may be a possible source of coronal heating by rapid footpoint motions that…

astro-ph2004

Phase diversity restoration of sunspot images I. Relations between penumbral and photospheric features

J. A. Bonet, I. Marquez, R. Muller +2

We investigate the dynamics of and the relations between small-scale penumbral and photospheric features near the outer penumbral boundary: penumbral grains (PGs), dark penumbral f…

hep-ex2024

Measurement of neutrino oscillation parameters with the first six detection units of KM3NeT/ORCA

KM3NeT Collaboration, S. Aiello, A. Albert +260

KM3NeT/ORCA is a water Cherenkov neutrino detector under construction and anchored at the bottom of the Mediterranean Sea. The detector is designed to study oscillations of atmosph…

astro-ph.HE2023

Searches for neutrinos in the direction of radio-bright blazars with the ANTARES telescope

ANTARES Collaboration, A. Albert, S. Alves +162

Active galaxies, especially blazars, are among the most promising neutrino source candidates. To date, ANTARES searches for these objects considered GeV-TeV -ray bright blazars…

astro-ph.HE2020

Combined search for neutrinos from dark matter self-annihilation in the Galactic Centre with ANTARES and IceCube

ANTARES Collaboration, A. Albert, M. André +495

We present the results of the first combined dark matter search targeting the Galactic Centre using the ANTARES and IceCube neutrino telescopes. For dark matter particles with mass…

cs.OH2008

Design Optimization for an Electro-Thermally Actuated Polymeric Microgripper

R. Voicu, R. Muller, L. Eftime

Thermal micro-actuators are a promising solution to the need for large-displacement, gentle handling force, low-power MEMS actuators. Potential applications of these devices are mi…

astro-ph.HE2023

Search for Gamma-Ray and Neutrino Coincidences Using HAWC and ANTARES Data

H. A. Ayala Solares, S. Coutu, D. Cowen +228

In the quest for high-energy neutrino sources, the Astrophysical Multimessenger Observatory Network (AMON) has implemented a new search by combining data from the High Altitude Wat…

astro-ph.HE2026

Constraining gamma-ray burst parameters with the first ultra-high energy neutrino event KM3-230213A

KM3NeT Collaboration, O. Adriani, A. Albert +278

Context: The detection of the highest energy neutrino observed to date by KM3NeT, with an estimated energy of 220 PeV, opens up new possibilities for the study and identification o…

hep-ex2025

Search for Magnetic Monopoles with the Complete ANTARES Dataset

A. Albert, S. Alves, M. André +137

This study presents a novel search for magnetic monopoles using data collected over a 14 year period (2008-2022) by the ANTARES neutrino telescope. The interaction of magnetic mono…

astro-ph.HE2024

Review of the online analyses of multi-messenger alerts and electromagnetic transient events with the ANTARES neutrino telescope

A. Albert, S. Alves, M. André +146

By constantly monitoring at least one complete hemisphere of the sky, neutrino telescopes are well designed to detect neutrinos emitted by transient astrophysical events. Real-time…

astro-ph.SR2013

Magnetic field strength distribution of magnetic bright points inferred from filtergrams and spectro-polarimetric data

D. Utz, J. Jurčák, A. Hanslmeier +3

Small scale magnetic fields can be observed on the Sun in G-band filtergrams as MBPs (magnetic bright points) or identified in spectro-polarimetric measurements due to enhanced sig…

astro-ph.IM2023

Embedded Software of the KM3NeT Central Logic Board

S. Aiello, A. Albert, S. Alves Garre +271

The KM3NeT Collaboration is building and operating two deep sea neutrino telescopes at the bottom of the Mediterranean Sea. The telescopes consist of latices of photomultiplier tub…

hep-ex2021

Determining the Neutrino Mass Ordering and Oscillation Parameters with KM3NeT/ORCA

S. Aiello, A. Albert, S. Alves Garre +239

The next generation of water Cherenkov neutrino telescopes in the Mediterranean Sea are under construction offshore France (KM3NeT/ORCA) and Sicily (KM3NeT/ARCA). The KM3NeT/ORCA d…

astro-ph2004

Bright points in the inter-network quiet Sun

J. Sanchez Almeida, I. Marquez, J. A. Bonet +2

High resolution G-band images of the interior of a supergranulation cell show ubiquitous Bright Points (some 0.3 BPs per Mm^2). They are located in intergranular lanes and often fo…

astro-ph.HE2020

ANTARES and IceCube Combined Search for Neutrino Point-like and Extended Sources in the Southern Sky

ANTARES Collaboration, A. Albert, M. André +498

A search for point-like and extended sources of cosmic neutrinos using data collected by the ANTARES and IceCube neutrino telescopes is presented. The data set consists of all the…

astro-ph.HE2025

Search for steady and flaring neutrino emission from cosmic sources using the complete ANTARES dataset

ANTARES Collaboration, A. Albert, S. Alves +139

ANTARES, a neutrino detector located in the depths of the Mediterranean Sea, operated successfully for over 15 years before being decommissioned in 2022. The telescope offered an i…

astro-ph.HE2024

Search for Neutrino Emission from GRB 221009A using the KM3NeT ARCA and ORCA detectors

S. Aiello, A. Albert, M. Alshamsi +273

Gamma-ray bursts are promising candidate sources of high-energy astrophysical neutrinos. The recent GRB 221009A event, identified as the brightest gamma-ray burst ever detected, pr…

astro-ph.HE2021

Search for neutrino counterparts of gravitational-wave events detected by LIGO and Virgo during run O2 with the ANTARES telescope

ANTARES Collaboration, A. Albert, M. André +135

An offline search for a neutrino counterpart to gravitational-wave (GW) events detected during the second observation run (O2) of Advanced-LIGO and Advanced-Virgo performed with AN…

astro-ph.HE2020

Monte Carlo simulations for the ANTARES underwater neutrino telescope

The ANTARES Collaboration, A. Albert, M. André +133

Monte Carlo simulations are a unique tool to check the response of a detector and to monitor its performance. For a deep-sea neutrino telescope, the variability of the environmenta…

physics.ins-det2019

Letter of Interest for a Neutrino Beam from Protvino to KM3NeT/ORCA

A. V. Akindinov, E. G. Anassontzis, G. Anton +88

The Protvino accelerator facility located in the Moscow region, Russia, is in a good position to offer a rich experimental research program in the field of neutrino physics. Of par…

hep-ex2021

Combined sensitivity of JUNO and KM3NeT/ORCA to the neutrino mass ordering

KM3NeT Collaboration, S. Aiello, A. Albert +275

This article presents the potential of a combined analysis of the JUNO and KM3NeT/ORCA experiments to determine the neutrino mass ordering. This combination is particularly interes…

hep-ex2023

Probing invisible neutrino decay with KM3NeT-ORCA

KM3NeT Collaboration, S. Aiello, A. Albert +252

In the era of precision measurements of the neutrino oscillation parameters, upcoming neutrino experiments will also be sensitive to physics beyond the Standard Model. KM3NeT/ORCA…

astro-ph.HE2021

Implementation and first results of the KM3NeT real-time core-collapse supernova neutrino search

KM3NeT Collaboration, S. Aiello, A. Albert +242

The KM3NeT research infrastructure is under construction in the Mediterranean Sea. KM3NeT will study atmospheric and astrophysical neutrinos with two multi-purpose neutrino detecto…

physics.ao-ph2021

Studying Bioluminescence Flashes with the ANTARES Deep Sea Neutrino Telescope

N. Reeb, S. Hutschenreuter, P. Zehetner +141

We develop a novel technique to exploit the extensive data sets provided by underwater neutrino telescopes to gain information on bioluminescence in the deep sea. The passive natur…

hep-ex2026

Testing Heavy Dark Matter Decay as the Origin of KM3-230213A

KM3NeT Collaboration, O. Adriani, J. A. Aguilar +287

This work explores the hypothesis that the ultra-high-energy neutrino event KM3-230213A originates from the decay of a heavy dark matter particle with a mass above PeV scale. The a…

astro-ph.IM2021

Nanobeacon: A time calibration device for the KM3NeT neutrino telescope

S. Aiello, A. Albert, M. Alshamsi +238

The KM3NeT Collaboration is currently constructing a multi-site high-energy neutrino telescope in the Mediterranean Sea consisting of matrices of pressure-resistant glass spheres,…

hep-ex2025

Search for non-standard neutrino interactions with the first six detection units of KM3NeT/ORCA

S. Aiello, A. Albert, A. R. Alhebsi +261

KM3NeT/ORCA is an underwater neutrino telescope under construction in the Mediterranean Sea. Its primary scientific goal is to measure the atmospheric neutrino oscillation paramete…

astro-ph.HE2022

Search for secluded dark matter towards the Galactic Centre with the ANTARES neutrino telescope

A. Albert, S. Alves, M. Andre +146

Searches for dark matter (DM) have not provided any solid evidence for the existence of weakly interacting massive particles in the GeV-TeV mass range. Coincidentally, the scale of…

astro-ph.IM2023

The Power Board of the KM3NeT Digital Optical Module: design, upgrade, and production

S. Aiello, A. Albert, S. Alves Garre +281

The KM3NeT Collaboration is building an underwater neutrino observatory at the bottom of the Mediterranean Sea consisting of two neutrino telescopes, both composed of a three-dimen…

astro-ph.HE2026

Optimizing the potential of KM3NeT in detecting core-collapse supernovae

KM3NeT Collaboration, O. Adriani, A. Albert +285

Core-collapse supernovae mark the end of life of massive stars. However, despite their importance in astrophysics, their underlying mechanisms remain unclear. Neutrinos that emerge…

astro-ph.IM2019

KM3NeT front-end and readout electronics system: hardware, firmware and software

The KM3NeT Collaboration, S. Aiello, F. Ameli +237

The KM3NeT research infrastructure being built at the bottom of the Mediterranean Sea will host water-Cherenkov telescopes for the detection of cosmic neutrinos. The neutrino teles…

hep-ex2021

Sensitivity to light sterile neutrino mixing parameters with KM3NeT/ORCA

S. Aiello, A. Albert, M. Alshamsi +245

KM3NeT/ORCA is a next-generation neutrino telescope optimised for atmospheric neutrino oscillations studies. In this paper, the sensitivity of ORCA to the presence of a light steri…

astro-ph.HE2023

Hint for a TeV neutrino emission from the Galactic Ridge with ANTARES

A. Albert, S. Alves, M. André +151

Interactions of cosmic ray protons, atomic nuclei, and electrons in the interstellar medium in the inner part of the Milky Way produce a -ray flux from the Galactic Ridge. If t…

astro-ph.SR2017

Temporal relations between magnetic bright points and the solar sunspot cycle

D. Utz, R. Muller, T. Van Doorsselaere

The Sun shows a global magnetic field cycle traditionally best visible in the photosphere as a changing sunspot cycle featuring roughly an 11 year period. In addition we know that…

adap-org1997

First Order Nonequilibrium Phase Transition in a Spatially Extended System

R. Muller, K. Lippert, A. Kuhnel +1

We investigate a system of harmonically coupled identical nonlinear constituents subject to noise in different spatial arrangements. For global coupling we find for infinitely many…

astro-ph.HE2024

Searches for neutrino counterparts of gravitational waves from the LIGO/Virgo third observing run with KM3NeT

KM3NeT Collaboration, S. Aiello, A. Albert +273

The KM3NeT neutrino telescope is currently being deployed at two different sites in the Mediterranean Sea. First searches for astrophysical neutrinos have been performed using data…

physics.ins-det2020

Dependence of atmospheric muon flux on seawater depth measured with the first KM3NeT detection units

KM3NeT Collaboration, M. Ageron, S. Aiello +262

KM3NeT is a research infrastructure located in the Mediterranean Sea, that will consist of two deep-sea Cherenkov neutrino detectors. With one detector (ARCA), the KM3NeT Collabora…

astro-ph.SR2012

Variations of magnetic bright point properties with longitude and latitude as observed by Hinode/SOT G-band data

D. Utz, A. Hanslmeier, A. Veronig +4

Small-scale magnetic fields can be observed on the Sun in high resolution G-band filtergrams as magnetic bright points (MBPs). We study Hinode/ Solar Optical Telescope (SOT) longit…

astro-ph.HE2021

ANTARES upper limits on the multi-TeV neutrino emission from the GRBs detected by IACTs

ANTARES Collaboration, A. Albert, M. André +135

The first gamma-ray burst detections by Imaging Atmospheric Cherenkov Telescopes have been recently announced: GRB 190114C, detected by MAGIC, GRB 180720B and GRB 190829A, observed…

astro-ph.HE2025

On the Potential Galactic Origin of the Ultra-High-Energy Event KM3-230213A

O. Adriani, S. Aiello, A. Albert +286

The KM3NeT observatory detected the most energetic neutrino candidate ever observed, with an energy between 72 PeV and 2.6 EeV at the 90% confidence level. The observed neutrino is…

astro-ph.HE2024

Prospects for combined analyses of hadronic emission from -ray sources in the Milky Way with CTA and KM3NeT

T. Unbehaun, L. Mohrmann, S. Funk +271

The Cherenkov Telescope Array and the KM3NeT neutrino telescopes are major upcoming facilities in the fields of -ray and neutrino astronomy, respectively. Possible simultaneous…

astro-ph.SR2015

Long-term trends of magnetic bright points: I. Number of MBPs at disc centre

D. Utz, R. Muller, S. Thonhofer +5

Context. The Sun shows an activity cycle that is caused by its varying global magnetic field. During a solar cycle, sunspots, i.e. extended regions of strong magnetic fields, occur…

astro-ph.HE2025

The ultra-high-energy event KM3-230213A within the global neutrino landscape

KM3NeT Collaboration, O. Adriani, S. Aiello +290

On February 13th, 2023, the KM3NeT/ARCA telescope detected a neutrino candidate with an estimated energy in the hundreds of PeVs. In this article, the observation of this ultra-hig…

hep-ex2025

Probing invisible neutrino decay with the first six detection units of KM3NeT/ORCA

S. Aiello, A. Albert, A. R. Alhebsi +273

In the era of precision measurements of neutrino oscillation parameters, it is necessary for experiments to disentangle discrepancies that may indicate physics beyond the Standard…

astro-ph.HE2025

First Searches for Dark Matter with the KM3NeT Neutrino Telescopes

KM3NeT Collaboration, S. Aiello, A. Albert +262

Indirect dark matter detection methods are used to observe the products of dark matter annihilations or decays originating from astrophysical objects where large amounts of dark ma…

hep-ex2024

Search for quantum decoherence in neutrino oscillations with six detection units of KM3NeT/ORCA

S. Aiello, A. Albert, A. R. Alhebsi +259

Neutrinos described as an open quantum system may interact with the environment which introduces stochastic perturbations to their quantum phase. This mechanism leads to a loss of…

astro-ph.HE2024

Constraints on the energy spectrum of the diffuse cosmic neutrino flux from the ANTARES neutrino telescope

ANTARES Collaboration, A. Albert, S. Alves +139

High-significance evidences of the existence of a high-energy diffuse flux of cosmic neutrinos have emerged in the last decade from several observations by the IceCube Collaboratio…

physics.comp-ph2025

Deep Learning Framework for Enhanced Neutrino Reconstruction of Single-line Events in the ANTARES Telescope

A. Albert, S. Alves, M. André +137

We present the -fit algorithm designed to improve the reconstruction of neutrino events detected by a single line of the ANTARES underwater telescope, usually associated with lo…

astro-ph.HE2022

Search for Magnetic Monopoles with ten years of the ANTARES neutrino telescope

ANTARES Collaboration, A. Albert, S. Alves +145

This work presents a new search for magnetic monopoles using data taken with the ANTARES neutrino telescope over a period of 10 years (January 2008 to December 2017). Compared to p…

astro-ph.IM2020

Deep-sea deployment of the KM3NeT neutrino telescope detection units by self-unrolling

The KM3NeT Collaboration, S. Aiello, A. Albert +252

KM3NeT is a research infrastructure being installed in the deep Mediterranean Sea. It will house a neutrino telescope comprising hundreds of networked moorings - detection units or…

astro-ph.HE2024

Astronomy potential of KM3NeT/ARCA

S. Aiello, A. Albert, M. Alshamsi +275

The KM3NeT/ARCA neutrino detector is currently under construction at 3500 m depth offshore Capo Passero, Sicily, in the Mediterranean Sea. The main science objectives are the detec…

astro-ph.HE2019

Sensitivity of the KM3NeT/ARCA neutrino telescope to point-like neutrino sources

The KM3NeT Collaboration, S. Aiello, S. E. Akrame +219

KM3NeT will be a network of deep-sea neutrino telescopes in the Mediterranean Sea. The KM3NeT/ARCA detector, to be installed at the Capo Passero site (Italy), is optimised for the…

hep-ex2022

Search for non-standard neutrino interactions with 10 years of ANTARES data

A. Albert, S. Alves, M. André +145

Non-standard interactions of neutrinos arising in many theories beyond the Standard Model can significantly alter matter effects in atmospheric neutrino propagation through the Ear…

astro-ph.IM2019

4MOST: Project overview and information for the First Call for Proposals

R. S. de Jong, O. Agertz, A. Agudo Berbel +335

We introduce the 4-metre Multi-Object Spectroscopic Telescope (4MOST), a new high-multiplex, wide-field spectroscopic survey facility under development for the four-metre-class Vis…

astro-ph.SR2009

Dynamics of isolated magnetic bright points derived from Hinode/SOT G-band observations

D. Utz, A. Hanslmeier, R. Muller +3

Small-scale magnetic fields in the solar photosphere can be identified in high-resolution magnetograms or in the G-band as magnetic bright points (MBPs). Rapid motions of these fie…

astro-ph.HE2023

Search for neutrino counterparts to the gravitational wave sources from LIGO/Virgo O3 run with the ANTARES detector

ANTARES Collaboration, A. Albert, S. Alves +150

Since 2015 the LIGO and Virgo interferometers have detected gravitational waves from almost one hundred coalescences of compact objects (black holes and neutron stars). This articl…

astro-ph.HE2020

Constraining the contribution of Gamma-Ray Bursts to the high-energy diffuse neutrino flux with 10 years of ANTARES data

ANTARES Collaboration, A. Albert, M. André +133

Addressing the origin of the astrophysical neutrino flux observed by IceCube is of paramount importance. Gamma-Ray Bursts (GRBs) are among the few astrophysical sources capable of…

astro-ph.IM2019

The Control Unit of the KM3NeT Data Acquisition System

S. Aiello, F. Ameli, M. Andre +217

The KM3NeT Collaboration runs a multi-site neutrino observatory in the Mediterranean Sea. Water Cherenkov particle detectors, deep in the sea and far off the coasts of France and I…