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

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

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

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

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

Future neutrino + Extensive Air Shower challenges

“Multimessenger” astrophysics, connecting traditional astronomy with cosmic ray (CR), γ-ray and neutrino observations, is a new branch of physics connecting particle physics, astrophysics and cosmology. It is made possible by the availability of experimental techniques and detectors developed for high-energy physics. These have allowed the realization of sensible detectors in space (for the measurement of the primary CR flux, search for primary antimatter, astrophysical studies of γ-ray sources up to hundreds of GeV), on the Earth surface (arrays of detectors for the study of the high energy component of CRs, the identification and characterizations of γ-ray sources up to hundreds of TeV), deep underground detectors (for studies of neutrino oscillations, measurement of solar neutrinos, searches for neutrinos from gravitational core-collapse of massive stars) and under kilometers of water or ice (detection of high-energy neutrinos emitted from astrophysical accelerators). The experimental identification of the engines (or class of engines) able to accelerate protons to energies orders of magnitude larger than in the LHC is one of major open problems in multimessenger astrophysics. In additions, almost all experiments enter in the game for the indirect searches for dark matter candidates. All the involved detectors are characterized by long term measurement campaigns in hostile or inaccessible environments, requiring stable, robust, low cost and low-power electronics detectors. Here, we present a brief outlook and perspectives for the multimessenger studies, with particular attentions to cosmic neutrinos and ground-based observatories of air shower