Antares: Towards a Large Underwater Neutrino Experiment

After a long R&D phase to validate its detector concept, the ANTARES (Astronomy with a Neutrino Telescope and Abyss environmental RESearch) collaboration is operating the largest neutrino telescope in the Northern hemisphere, which is close to completion. It is located in the Mediterranean Sea, offshore from Toulon in France at a depth of 2500 m of water which provide a shield from cosmic rays. The detector design is based on the reconstruction of events produced by neutrino interactions. The expected angular resolution for high energy muon neutrinos (E>10 TeV) is less than 0.3 deg. To achieve this good angular resolution, severe requirements on the time resolution of the detected photons and on the determination of the relative position of the detection devices must be reached. The full 12-line detector is planned to be fully operational during this year. At present (April 2008) there are 10 lines taking data plus an instrumented line deployed at the edge of the detector to monitor environmental sea parameters. This paper describes the design of the detector as well as some results obtained during the 2007 5-line run (from March to December).Comment: Contribution to the Rencontres de Physique, La Thuile, 24/2-1/3 2008. 16 pages and 8 figure

MACRO and the atmospheric neutrino problem

After a brief presentation of the MACRO detector we discuss the updated data on atmospheric muon neutrinos, and the interpretation in terms of neutrino oscillations.Comment: 6 pages, 4 figures. Invited talk at the Third International Workshop on New Worlds in Astroparticle Physics 1-3 September 2000, University of the Algarve. Faro, Portuga

Results from the ANTARES Neutrino Telescope

A primary goal of a deep-sea neutrino telescopes as ANTARES is the search for astrophysical neutrinos in the TeV-PeV range. ANTARES is today the largest neutrino telescope in the Northern hemisphere. After the discovery of a cosmic neutrino diffuse flux by the IceCube, the understanding of its origin has become a key mission in high-energy astrophysics. ANTARES makes a valuable contribution for sources located in the Southern sky thanks to its excellent angular resolution in both the muon channel and the cascade channel (induced by all neutrino flavors). Assuming various spectral indexes for the energy spectrum of neutrino emitters, the Southern sky and in particular central regions of our Galaxy are studied searching for point-like objects and for extended regions of emission. In parallel, by adopting a multimessenger approach, based on time and/or space coincidences with other cosmic probes, the sensitivity of such searches can be considerably augmented. ANTARES has participated to a high-energy neutrino follow-up of the gravitational wave signal GW150914, providing the first constraint on high-energy neutrino emission from a binary black hole coalescence. ANTARES has also performed indirect searches for Dark Matter, yielding limits for the spin-dependent WIMP-nucleon cross-section that improve upon those of current direct-detection experiments.Comment: Proceedings of the CRIS2016 (10th Cosmic Ray International Seminar) - Ischia (NA) Italy, July 4-8, 201

Constraints to a Galactic Component of the Ice Cube cosmic neutrino flux from ANTARES

The IceCube evidence for cosmic neutrinos in the high-energy starting events (HESE) sample has inspired a large number of hypothesis on their origin, mainly due to the poor precision on the measurement of the direction of showering events. The fact that most of HESE are downward going suggests a possible Galactic component. This could be originated either by a single point-like source or to a directional excess from an extended Galactic region. These hypotheses are reviewed and constrained, using the present available upper limits from the ANTARES neutrino telescope. ANTARES detects $\nu_\mu$ from sources in the Southern sky with an effective area larger than that providing the IceCube HESE for $E_\nu<60$ TeV and a factor of about two smaller at 1 PeV. The use of the $\nu_\mu$ signal enables an accurate measurement of the incoming neutrino direction. The Galactic signal allowed by the IceCube HESE and the corresponding ANTARES limits are studied in terms of a power law flux $E^{-\Gamma}$, with spectral index $\Gamma$ ranging from 2.0 to 2.5 to cover most astrophysical models

A parameterisation of single and multiple muons in the deep water or ice

Atmospheric muons play an important role in underwater/ice neutrino detectors. In this paper, a parameterisation of the flux of single and multiple muon events, their lateral distribution and of their energy spectrum is presented. The kinematics parameters were modelled starting from a full Monte Carlo simulation of the interaction of primary cosmic rays with atmospheric nuclei; secondary muons reaching the sea level were propagated in the deep water. The parametric formulas are valid for a vertical depth of 1.5-5 km w.e. and up to 85 deg for the zenith angle, and can be used as input for a fast simulation of atmospheric muons in underwater/ice detectors.Comment: 25 pages, 8 figure

Misura della raccolta di luce in una striscia di scintillatore plastico letta con fotomoltiplicatori al silicio

In questo lavoro è stata studiata la risposta a particelle al minimo di ionizzazione di un rivelatore, che sarà utilizzato per l'identificazione di muoni in SHIP (Search for HIdden Particles), esperimento proposto al CERN e ancora in fase di approvazione. Il rivelatore è basato su una striscia di scintillatore lunga tre metri accoppiata ad una fibra ottica Wave Lenght Shifter (WLS) e letta da due fotomoltiplicatori al Silicio (SiPM), posti ad entrambi i capi. Lo scopo principale del lavoro è la misura della raccolta di luce del rivelatore e la valutazione della lunghezza di attenuazione della striscia. I risultati mostrano che, nonostante l'attenuazione, la configurazione scelta per il rivelatore è tale da garantire una buona raccolta di luce lungo tutta la striscia

Physics and astrophysics with high energy v in MACRO

The events collected with the lower part of the MACRO detector at the Gran Sasso Laboratory have been analyzed looking for neutrino-induced muons. Upward throughgoing events have been measured and the result is compared with Monte Carlo prediction. The first results concerning upward stopping muons and partially contained events are also reported. A search has been made for astrophysical point sources of neutrinos. No point sources have been observed