Limits on the nuclearite flux using the ANTARES neutrino telescope

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 particles is simulated %according to the model of de R\'{u}jula and Glashow taking into account a detailed description of the detector response to nuclearites and of the data acquisition conditions. A down-going flux of cosmic nuclearites with Galactic velocities ($\beta = 10^{-3}$) was considered for this study. The mass threshold for detecting these particles at the detector level is \mbox{ $4 \times 10^{13}$ GeV/c$^{2}$}. Upper limits on the nuclearite flux for masses up to $10^{17}$ GeV/c$^{2}$ at the level of $\sim 5 \times 10^{-17}$ cm$^{-2}$ s$^{-1}$ sr$^{-1}$ are obtained. These are the first upper limits on nuclearites established with a neutrino telescope and the most stringent ever set for Galactic velocities.Comment: 17 pages, 7 figure

Search for magnetic monopoles with ten years of the ANTARES neutrino telescope

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 previous ANTARES searches, this analysis uses a run-by-run simulation strategy, with a larger exposure as well as a new simulation of magnetic monopoles taking into account the Kasama, Yang and Goldhaber model for their interaction cross-section with matter. No signal compatible with the passage of relativistic magnetic monopoles is observed, and upper limits on the flux of magnetic monopoles with β=v/c≥0.55, are presented. For ultra-relativistic magnetic monopoles the flux limit is ∼7×10−18 cm−2s−1sr−1

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

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 stacking method is used to assess the significance of an excess of muon neutrinos inducing track-like events in correlation with the location of a list of possible sources. Different sets of objects are tested in the analysis: a) a sub-sample of the \textit{Fermi} 3LAC catalog of blazars, b) a jet-obscured AGN population, c) a sample of soft gamma-ray selected radio galaxies, d) a star-forming galaxy catalog , and e) a public sample of 56 very-high-energy track events from the IceCube experiment. None of the tested sources shows a significant association with the sample of neutrinos detected by ANTARES. The smallest p-value is obtained for the radio galaxies catalog with an equal weights hypothesis, with a pre-trial p-value equivalent to a $2.8 \, \sigma$ excess, equivalent to $1.6 \, \sigma$ post-trial. In addition, the results of a dedicated analysis for the blazar MG3 J225517+2409 are also reported: this source is found to be the most significant within the \textit{Fermi} 3LAC sample, with 5 ANTARES events located at less than one degree from the source. This blazar showed evidence of flaring activity in \textit{Fermi} data, in space-time coincidence with a high-energy track detected by IceCube. An \emph{a posteriori} significance of $2.0\, \sigma$ for the combination of ANTARES and IceCube data is reported

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

[EN] The ANTARES detector is an undersea neutrino telescope in the Mediterranean Sea. The search for pointlike neutrino sources is one of the main goals of the ANTARES telescope, requiring a reliable method to evaluate the detector angular resolution and pointing accuracy. This work describes the study of the Sun ¿shadow¿ effect with the ANTARES detector. The shadow is the deficit in the atmospheric muon flux in the direction of the Sun caused by the absorption of the primary cosmic rays. This analysis is based on the data collected between 2008 and 2017 by the ANTARES telescope. The observed statistical significance of the Sun shadow detection is 3.7¿, with an estimated angular resolution of 0.59° +- 0.10°for downward-going muons. The pointing accuracy is found to be consistent with the expectations and no evidence of systematic pointing shifts is observed.The authors acknowledge the financial support of the funding agencies: Centre National de la Recherche Scientifique, Commissariat `a l'' energie atomique et aux energies alternatives, Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France, LabEx UnivEarthS (ANR-10-LABX-0023 and ANR-18-IDEX-0001), R ' egion Ile-de-France (DIM-ACAV), Region Alsace (contract CPER), Region Provence-Alpes-Cote d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung, Germany; Istituto Nazionale di Fisica Nucleare, Italy; Nederlandse organisatie voor Wetenschappelijk Onderzoek, the Netherlands; Council of the President of the Russian Federation for Young Scientists and Leading Scientific Schools supporting grants, Russia; Executive Unit for Financing Higher Education, Research, Development and Innovation (UEFISCDI), Romania; Ministerio de Ciencia, Innovacion, Investigacion y Universidades (MCIU): Programa Estatal de Generacion de Conocimiento (refs. PGC2018-096663-B-C41, -A-C42, -B-C43, -B-C44) (MCIU/FEDER), Severo Ochoa Centre of Excellence and MultiDark Consolider (MCIU), Junta de Andalucia (refs. SOMM17/6104/UGR and A-FQM-053-UGR18), Generalitat Valenciana: Grisolia (ref. GRISOLIA/2018/119), Spain; Ministry of Higher Education, Scientific Research and Professional Training, Morocco. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and the CC-IN2P3 for the computing facilities.Albert, A.; Andre, M.; Anghinolfi, M.; Anton, G.; Ardid Ramírez, M.; Aubert, J.; Aublin, J.... (2020). Observation of the cosmic ray shadow of the Sun with the ANTARES neutrino telescope. Physical Review D: covering particles, fields, gravitation, and cosmology. 102(12):1-7. https://doi.org/10.1103/PhysRevD.102.122007S1710212Ageron, M., Aguilar, J. A., Al Samarai, I., Albert, A., Ameli, F., André, M., … Ardid, M. (2011). ANTARES: The first undersea neutrino telescope. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 656(1), 11-38. doi:10.1016/j.nima.2011.06.103Alexandreas, D. E., Allen, R. C., Berley, D., Biller, S. D., Burman, R. L., Cady, D. R., … Zhang, W. (1991). Observation of shadowing of ultrahigh-energy cosmic rays by the Moon and the Sun. Physical Review D, 43(5), 1735-1738. doi:10.1103/physrevd.43.1735Andreyev, Y. M., Zakidyshev, V. N., Karpov, S. N., & Khodov, V. N. (2002). Cosmic Research, 40(6), 559-564. doi:10.1023/a:1021553713199Borione, A., Catanese, M., Covault, C. E., Cronin, J. W., Fick, B. E., Gibbs, K. G., … van der Velde, J. C. (1994). Observation of the shadows of the Moon and Sun using 100 TeV cosmic rays. Physical Review D, 49(3), 1171-1177. doi:10.1103/physrevd.49.1171Cobb, J. H., Marshak, M. L., Allison, W. W. M., Alner, G. J., Ayres, D. S., Barrett, W. L., … Wall, D. (2000). Observation of a shadow of the Moon in the underground muon flux in the Soudan 2 detector. Physical Review D, 61(9). doi:10.1103/physrevd.61.092002Bartoli, B., Bernardini, P., Bi, X. J., Bleve, C., Bolognino, I., Branchini, P., … Cao, Z. (2012). Measurement of the cosmic ray antiproton/proton flux ratio at TeV energies with the ARGO-YBJ detector. Physical Review D, 85(2). doi:10.1103/physrevd.85.022002Abeysekara, A. U., Albert, A., Alfaro, R., Alvarez, C., Álvarez, J. D., Arceo, R., … Belmont-Moreno, E. (2018). Constraining the p¯/p ratio in TeV cosmic rays with observations of the Moon shadow by HAWC. Physical Review D, 97(10). doi:10.1103/physrevd.97.102005Adamson, P., Andreopoulos, C., Ayres, D. S., Backhouse, C., Barr, G., Barrett, W. L., … Bock, G. J. (2011). Observation in the MINOS far detector of the shadowing of cosmic rays by the sun and moon. Astroparticle Physics, 34(6), 457-466. doi:10.1016/j.astropartphys.2010.10.010Aartsen, M. G., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., … Ansseau, I. (2019). Detection of the Temporal Variation of the Sun’s Cosmic Ray Shadow with the IceCube Detector. The Astrophysical Journal, 872(2), 133. doi:10.3847/1538-4357/aaffd1Albert, A., André, M., Anghinolfi, M., Anton, G., Ardid, M., Aubert, J.-J., … Barrios-Martít, J. (2018). The cosmic ray shadow of the Moon observed with the ANTARES neutrino telescope. The European Physical Journal C, 78(12). doi:10.1140/epjc/s10052-018-6451-3First search for neutrinos in correlation with gamma-ray bursts with the ANTARES neutrino telescope. (2013). Journal of Cosmology and Astroparticle Physics, 2013(03), 006-006. doi:10.1088/1475-7516/2013/03/006Aguilar, J. A., Al Samarai, I., Albert, A., André, M., Anghinolfi, M., Anton, G., … Astraatmadja, T. (2011). A fast algorithm for muon track reconstruction and its application to the ANTARES neutrino telescope. Astroparticle Physics, 34(9), 652-662. doi:10.1016/j.astropartphys.2011.01.003BECHERINI, Y., MARGIOTTA, A., SIOLI, M., & SPURIO, M. (2006). A parameterisation of single and multiple muons in the deep water or ice. Astroparticle Physics, 25(1), 1-13. doi:10.1016/j.astropartphys.2005.10.005Carminati, G., Bazzotti, M., Margiotta, A., & Spurio, M. (2008). Atmospheric MUons from PArametric formulas: a fast GEnerator for neutrino telescopes (MUPAGE). Computer Physics Communications, 179(12), 915-923. doi:10.1016/j.cpc.2008.07.014Yepes-Ramírez, H. (2013). Characterization of optical properties of the site of the ANTARES neutrino telescope. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 725, 203-206. doi:10.1016/j.nima.2012.11.143Fusco, L. A., & Margiotta, A. (2016). The Run-by-Run Monte Carlo simulation for the ANTARES experiment. EPJ Web of Conferences, 116, 02002. doi:10.1051/epjconf/201611602002Albert, A., André, M., Anghinolfi, M., Anton, G., Ardid, M., Aubert, J.-J., … Basa, S. (2017). First all-flavor neutrino pointlike source search with the ANTARES neutrino telescope. Physical Review D, 96(8). doi:10.1103/physrevd.96.082001Albert, A., André, M., Anghinolfi, M., Anton, G., Ardid, M., Aubert, J.-J., … Belhorma, B. (2020). ANTARES and IceCube Combined Search for Neutrino Point-like and Extended Sources in the Southern Sky. The Astrophysical Journal, 892(2), 92. doi:10.3847/1538-4357/ab7afbAdrián-Martínez, S., Albert, A., André, M., Anghinolfi, M., Anton, G., Ardid, M., … Basa, S. (2014). SEARCHES FOR POINT-LIKE AND EXTENDED NEUTRINO SOURCES CLOSE TO THE GALACTIC CENTER USING THE ANTARES NEUTRINO TELESCOPE. The Astrophysical Journal, 786(1), L5. doi:10.1088/2041-8205/786/1/l

Search for neutrino counterparts to the gravitational wave sources from O3 catalogues with the ANTARES detector

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 article presents the results of a search performed with data from the ANTARES telescope to identify neutrino counterparts to the gravitational wave sources detected during the third LIGO/Virgo observing run and reported in the catalogues GWTC-2, GWTC-2.1, and GWTC-3. This search is sensitive to all-sky neutrinos of all flavours and of energies $>100\,$GeV, thanks to the inclusion of both track-like events (mainly induced by $\nu_\mu$ charged-current interactions) and shower-like events (induced by other interaction types). Neutrinos are selected if they are detected within $\pm 500\,$s from the GW merger and with a reconstructed direction compatible with its sky localisation. No significant excess is found for any of the 80 analysed GW events, and upper limits on the neutrino emission are derived. Using the information from the GW catalogues and assuming isotropic emission, upper limits on the total energy $E_{\rm tot, \nu}$ and on the fraction of the total energy budget $f_\nu = E_{\rm tot, \nu}/E_{\rm rad}$ emitted as neutrinos of all flavours are also computed. Finally, a stacked analysis of all the 72 binary black hole mergers (respectively the 7 neutron star - black hole merger candidates) has been performed to constrain the typical neutrino emission within this population, leading to the limits: $E_{\rm tot, \nu} < 4.0 \times 10^{53}\,$erg and $f_\nu < 0.15$ (respectively, $E_{\rm tot, \nu} < 3.2 \times 10^{53}\,$erg and $f_\nu < 0.88$) for $E^{-2}$ spectrum and isotropic emission. Other assumptions including softer spectra and non-isotropic scenarios have also been tested.Comment: 13 pages, 4 figure

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

Active galaxies, especially blazars, are among the most promising neutrino source candidates. To date, ANTARES searches for these objects considered GeV-TeV $\gamma$-ray bright blazars. Here, a statistically complete radio-bright blazar sample is used as the target for searches of origins of neutrinos collected by the ANTARES neutrino telescope over 13 years of operation. The hypothesis of a neutrino-blazar directional correlation is tested by pair counting and by a complementary likelihood-based approach. The resulting post-trial $p$-value is $3.0\%$ ($2.2\sigma$ in the two-sided convention), possibly indicating a correlation. Additionally, a time-dependent analysis is performed to search for temporal clustering of neutrino candidates as a mean of detecting neutrino flares in blazars. None of the investigated sources alone reaches a significant flare detection level. However, the presence of 18 sources with a pre-trial significance above $3\sigma$ indicates a $p=1.4\%$ ($2.5\sigma$ in the two-sided convention) detection of a time-variable neutrino flux. An \textit{a posteriori} investigation reveals an intriguing temporal coincidence of neutrino, radio, and $\gamma$-ray flares of the J0242+1101 blazar at a $p=0.5\%$ ($2.9\sigma$ in the two-sided convention) level. Altogether, the results presented here suggest a possible connection of neutrino candidates detected by the ANTARES telescope with radio-bright blazars

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

The authors acknowledge the financial support of the funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariat a l'Energie Atomique et aux Energies Alternatives(CEA), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), Labex UnivEarthS(ANR-10-LABX-0023 and ANR-18-IDEX-0001), Region Ile-de-France (DIM-ACAV), Region Alsace (contrat CPER), Region Provence-AlpesCote d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Instituto Nazionale di Fisica Nucleare(INFN), Italy; Nederlandse Organisatie voor Wetenschappelijk Onderzoek(NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; Executive Unit for Financing Higher Education, Research, Development and Innovation (UEFISCDI), Romania; Ministerio de Ciencia e Innovacion (MCI) and Agencia Estatal de Investigacion: Programa Estatal de Generacion de Conocimiento (refs. PGC2018096663-B-C41, -A-C42, -B-C43, -B-C44) (MCI/FEDER), Severo Ochoa Centre of Excellence and MultiDark Consolider, Junta de Andalucia (ref. SOMM17/6104/UGR and A-FQM-053-UGR18), Generalitat Valenciana: Grisolia (ref. GRISOLIA/2018/119) and GenT (ref. CIDEGENT/2018/034) programs, Spain; Ministry of Higher Education, Scientific Research and Professional Training, Morocco. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and the CC-IN2P3 for the computing facilities. The authors acknowledge the financial support of the funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariat a l'Energie Atomique et aux Energies Alternatives(CEA), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), Labex UnivEarthS(ANR-10-LABX-0023 and ANR-18-IDEX-0001), Region Ile-de-France (DIM-ACAV), Region Alsace (contrat CPER), Region Provence-AlpesCote d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Instituto Nazionale di Fisica Nucleare(INFN), Italy; Nederlandse Organisatie voor Wetenschappelijk Onderzoek(NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; Executive Unit for Financing Higher Education, Research, Development and Innovation (UEFISCDI), Romania; Ministerio de Ciencia e Innovacion (MCI) and Agencia Estatal de Investigacion: Programa Estatal de Generacion de Conocimiento (refs. PGC2018096663-B-C41, -A-C42, -B-C43, -B-C44) (MCI/FEDER), Severo Ochoa Centre of Excellence and MultiDark Consolider, Junta de Andalucia (ref. SOMM17/6104/UGR and A-FQM-053-UGR18), Generalitat Valenciana: Grisolia (ref. GRISOLIA/2018/119) and GenT (ref. CIDEGENT/2018/034) programs, Spain; Ministry of Higher Education, Scientific Research and Professional Training, Morocco. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and the CC-IN2P3 for the computing facilities.This letter presents a combined measurement of the energy spectra of atmospheric nu(e) and nu(mu) in the energy range between similar to 100 GeV and similar to 50 TeV with the ANTARES neutrino telescope. The analysis uses 3012 days of detector livetime in the period 2007-2017, and selects 1016 neutrinos interacting in (or close to) the instrumented volume of the detector, yielding shower-like events (mainly from nu(e) + (nu) over bar (e) charged current plus all neutrino neutral current interactions) and starting track events (mainly from nu(mu) + (nu) over bar (mu) charged current interactions). The contamination by atmospheric muons in the final sample is suppressed at the level of a few per mill by different steps in the selection analysis, including a Boosted Decision Tree classifier. The distribution of reconstructed events is unfolded in terms of electron and muon neutrino fluxes. The derived energy spectra are compared with previous measurements that, above 100 GeV, are limited to experiments in polar ice and, for nu(mu), to Super-Kamiokande.Centre National de la Recherche Scientifique (CNRS)French Atomic Energy CommissionCommission Europeenne (FEDER fund)Institut Universitaire de France (IUF)Labex UnivEarthS ANR-10-LABX-0023 ANR-18-IDEX-0001Region Ile-de-FranceRegion Grand-EstRegion Provence-Alpes-Cote d'AzurRegion Provence-Alpes-Cote d'AzurFederal Ministry of Education & Research (BMBF)Instituto Nazionale di Fisica Nucleare(INFN), ItalyNetherlands Organization for Scientific Research (NWO)Netherlands GovernmentCouncil of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, RussiaConsiliul National al Cercetarii Stiintifice (CNCS)Unitatea Executiva pentru Finantarea Invatamantului Superior, a Cercetarii, Dezvoltarii si Inovarii (UEFISCDI)Spanish Government PGC2018096663-B-C41 PGC2018096663-A-C42 PGC2018096663-B-C43 PGC2018096663-B-C44Severo Ochoa Centre of Excellence and MultiDark ConsoliderJunta de Andalucia SOMM17/6104/UGR A-FQM-053-UGR18Generalitat Valenciana: Grisolia program, Spain GRISOLIA/2018/119Generalitat Valenciana: GenT program, Spain CIDEGENT/2018/034Ministry of Higher Education, Scientific Research and Professional Training, MoroccoAgencia Estatal de Investigacion PGC2018096663-B-C41 PGC2018096663-A-C42 PGC2018096663-B-C43 PGC2018096663-B-C44Commission Europeenne (Marie Curie Program

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

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 Water Cherenkov (HAWC) observatory and the Astronomy with a Neutrino Telescope and Abyss environmental RESearch (ANTARES) neutrino telescope. Using the same analysis strategy as in a previous detector combination of HAWC and IceCube data, we perform a search for coincidences in HAWC and ANTARES events that are below the threshold for sending public alerts in each individual detector. Data were collected between July 2015 and February 2020 with a livetime of 4.39 years. Over this time period, 3 coincident events with an estimated false-alarm rate of $< 1$ coincidence per year were found. This number is consistent with background expectations.Comment: 12 pages, 5 figures, 3 table

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

[EN] 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 track-like and shower-like events pointing in the direction of the Southern Sky included in the nine-year ANTARES point-source analysis, combined with the throughgoing track-like events used in the seven-year IceCube point-source search. The advantageous ¿eld of view of ANTARES and the large size of IceCube are exploited to improve the sensitivity in the Southern Sky by a factor of ~2 compared to both individual analyses. In this work, the Southern Sky is scanned for possible excesses of spatial clustering, and the positions of preselected candidate sources are investigated. In addition, special focus is given to the region around the Galactic Center, whereby a dedicated search at the location of SgrA* is performed, and to the location of the supernova remnant RXJ 1713.7-3946. No signi¿cant evidence for cosmic neutrino sources is found, and upper limits on the ¿ux from the various searches are presented.The authors of the IceCube Collaboration acknowledge the support from the following agencies and institutions: USA-U.S. National Science Foundation-Office of Polar Programs, U.S. National Science Foundation-Physics Division, Wisconsin Alumni Research Foundation, Center for High Throughput Computing (CHTC) at the University of Wisconsin-Madison, Open Science Grid (OSG), Extreme Science and Engineering Discovery Environment (XSEDE), U.S. Department of Energy-National Energy Research Scientific Computing Center, Particle astrophysics research computing center at the University of Maryland, Institute for Cyber-Enabled Research at Michigan State University, and Astroparticle physics computational facility at Marquette University; Belgium-Funds for Scientific Research (FRS-FNRS and FWO), FWO Odysseus and Big Science programmes, and Belgian Federal Science Policy Office (Belspo); Germany-Bundesministerium fur Bildung und Forschung (BMBF), Deutsche Forschungsgemeinschaft (DFG), Helmholtz Alliance for Astroparticle Physics (HAP), Initiative and Networking Fund of the Helmholtz Association, Deutsches Elektronen Synchrotron (DESY), and High Performance Computing Cluster of the RWTH Aachen; Sweden-Swedish Research Council, Swedish Polar Research Secretariat, Swedish National Infrastructure for Computing (SNIC), and Knut and Alice Wallenberg Foundation; Australia - Australian Research Council; Canada-Natural Sciences and Engineering Research Council of Canada, Calcul Quebec, Compute Ontario, Canada Foundation for Innovation, WestGrid, and Compute Canada; Denmark-Villum Fonden, Danish National Research Foundation (DNRF), Carlsberg Foundation; New Zealand-Marsden Fund; Japan-Japan Society for Promotion of Science (JSPS) and Institute for Global Prominent Research (IGPR) of Chiba University; Korea-National Research Foundation of Korea (NRF); Switzerland-Swiss National Science Foundation (SNSF); United Kingdom-Department of Physics, University of Oxford.Albert, A.; Andre, M.; Anghinolfi, M.; Anton, G.; Ardid Ramírez, M.; Aubert, J.; Aublin, J.... (2020). ANTARES and IceCube Combined Search for Neutrino Point-like and Extended Sources in the Southern Sky. The Astrophysical Journal. 892(2):1-12. https://doi.org/10.3847/1538-4357/ab7afbS112892

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

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 strings — equipped with optical instrumentation to detect the Cherenkov radiation generated by charged particles from neutrino-induced collisions in its vicinity. In comparison to moorings typically used for oceanography, several key features of the KM3NeT string are different: the instrumentation is contained in transparent and thus unprotected glass spheres; two thin Dyneema® ropes are used as strength members; and a thin delicate backbone tube with fibre-optics and copper wires for data and power transmission, respectively, runs along the full length of the mooring. Also, compared to other neutrino telescopes such as ANTARES in the Mediterranean Sea and GVD in Lake Baikal, the KM3NeT strings are more slender to minimise the amount of material used for support of the optical sensors. Moreover, the rate of deploying a large number of strings in a period of a few years is unprecedented. For all these reasons, for the installation of the KM3NeT strings, a custom-made, fast deployment method was designed. Despite the length of several hundreds of metres, the slim design of the string allows it to be compacted into a small, re-usable spherical launching vehicle instead of deploying the mooring weight down from a surface vessel. After being lowered to the seafloor, the string unfurls to its full length with the buoyant launching vehicle rolling along the two ropes. The design of the vehicle, the loading with a string, and its underwater self-unrolling are detailed in this paper.French National Research Agency (ANR) ANR-15-CE31-0020Centre National de la Recherche Scientifique (CNRS)European Union (EU)Institut Universitaire de France (IUF)LabEx UnivEarthS ANR-10-LABX-0023 ANR-18-IDEX-0001Paris Ile-de-France Region, FranceShota Rustaveli National Science Foundation of Georgia (SRNSFG), Georgia FR-18-1268German Research Foundation (DFG)Greek Ministry of Development-GSRTIstituto Nazionale di Fisica Nucleare (INFN), Ministero dell'Universita e della Ricerca (MUR), PRIN Italy NAT-NET 2017W4HA7SMinistry of Higher Education, Scientific Research and Professional Training, MoroccoNetherlands Organization for Scientific Research (NWO) Netherlands GovernmentNational Science Center, Poland National Science Centre, Poland 2015/18/E/ST2/00758National Authority for Scientific Research (ANCS), RomaniaMinisterio de Ciencia, Innovación, Investigación y Universidades (MCIU): Programa Estatal de Generación de Conocimiento (MCIU/FEDER) PGC2018-096663-B-C41 PGC2018-096663-B-A-C42 PGC2018-096663-B-BC43 PGC2018-096663-B-B-C44Severo Ochoa Centre of Excellence and MultiDark Consolider (MCIU), Junta de Andalucía SOMM17/6104/UGRGeneralitat Valenciana GRISOLIA/2018/119 CIDEGENT/2018/034La Caixa Foundation LCF/BQ/IN17/11620019EU: MSC program, Spain 71367