D. Fargion

Muon and Gamma Bundles tracing Up-going Tau Neutrino Astronomy

Up-going and Horizontal Tau Air-Showers, UpTaus and HorTaus, may trace Ultra High Energy Neutrino Tau Earth Skimming at the edge of the horizons. Their secondaries ( μ ± and γ bundles with e ± pair flashes) might trace their nature over UHECR secondaries in horizontal showers. Indeed the atmosphere act as a perfect amplifier as well as a filter for showers: down-ward and horizontal μ bundles may still be originated by far Ultra High Energy Cosmic Rays skimming the terrestrial atmosphere but their rich gamma component will be exponentially suppressed. At large zenith angles after crossing a large slant depth ( X max > 3 × 10 3 g cm −2 ) the number of μ ± and secondary γ s (produced by the e ± pair from μ decay in flight) is comparable. On the other hand, up-ward muon bundles from UpTaus and HorTaus may arise within a young shower with a larger gamma-muon ratio (∼ 10 2 ), leaving its characteristic imprint. We estimate the UpTaus and HorTaus rate from the Earth and we evaluate the consequent event rate of μ ± , e ± and γ bundles. We show that such events even for minimal GZK neutrino fluxes could be detected by scintillator arrays placed on mountains at 1 −5 km and pointing to the horizon. The required array areas are within tens-hundreds of square meters. An optimal structure is an array of crown-like twin detectors facing the horizons. We argue that such detectors will be able to detect both muonic bundles at a minimal average flux of 10 −11 cm −2 s −1 sr −1 and electromagnetic particles ( γ , e ± ) at 3 × 10 −9 cm −2 s −1 sr −1 , a few times each year, even for the minimal GZK ν flux.

ON THE POSSIBILITY OF DETECTING THE ANNIHILATION OF VERY HEAVY NEUTRINOS IN THE GALACTIC HALO BY 1 km3 NEUTRINO DETECTOR

We consider the possibility of detecting in a hypothetical 1 km3 neutrino telescope high energy neutrinos resulting from the annihilation of very heavy neutrinos of fourth generation in the galactic halo. It is shown that such a large telescope could in principle detect this negligible component which, if it does exist, gives a contribution of order 10–2 to the dark matter of the universe.

UHECR narrow clustering correlating IceCube through-going muons

Abstract The recent UHECR events by AUGER and the Telescope Array (TA) suggested that wide clusterings as the North and South, named Hot Spot, are related to near AGNs such as the one in M82 and Cen A (as most authors and us convened). In the same frame since 2008 we assumed that the UHECR are made by light and lightest nuclei to explain the otherwise embarrassing absence of the huge nearby Virgo cluster, absence due to the fragility and the opacity of lightest nuclei by photo-dissociation from Virgo distances. Moreover UHECR map exhibits a few narrow clustering, some near the galactic plane, as toward SS 433 and on the opposite side of the plane at celestial horizons: we tagged them in 2014 suggesting possible near source active also as a UHE neutrino. Indeed since last year, 2015, highest IceCube trough-going muons, UHE up-going neutrino events at hundreds TeV energy, did show (by two cases over three tagged in North sky) the expected overlapping of UHE neutrinos signals with narrow crowding UHECR. New recent data with higher energy threshold somehow re-confirmed our preliminary proposal offering also new possible sources by a additional correlated UHE-neutrino versus UHE-neutrino and-or with narrow UHECR clustering events.

Shadows of Relic Neutrino Masses and Spectra on Highest Energy GZK Cosmic Rays

The Ultra High Energy (UHE) neutrino scattering onto relic cosmic neutrinos in galactic and local halos offers an unique way to overcome GZK cut-off. The UHE nu secondary of UHE photo-pion decays may escape the GZK cut-off and travel on cosmic distances hitting local light relic neutrinos clustered in dark halos. The Z resonant production and the competitive W^+W^-, ZZ pair production define a characteristic imprint on hadronic consequent UHECR spectra. This imprint keeps memory both of the primary UHE nu spectra as well as of the possible relic neutrino masses values, energy spectra and relic densities. Such an hadronic showering imprint should reflect into spectra morphology of cosmic rays near and above GZK 10^{19}-10^{21}eV cut-off energies. A possible neutrino degenerate masses at eVs or a more complex and significant neutrino mass split below or near Super-Kamiokande triangle m_{nu_{SK}}= 0.1 eV masses might be reflected after each corresponding Z peak showering, into new twin unexpected UHECR flux modulation behind GZK energies: E_{p} sim 3(frac{triangle m_{nu_{SK}}}/m_{nu}10^{21}),eV. nOther shadowsof lightest, nearly massless, neutrinos m_{nu_{2K} simeq 0.001eV simeq kT_{nu}, their lowest relic temperatures, energies and densities might be also reflected at even higher energies edges near Grand Unification: E_{p} sim 2.2(m_{nu_{2K}/E_{nu}})10^{23}, eV .

Signals of HE atmospheric μ decay in flight around the Sun’s albedo versus astrophysical νμ and ντ traces in the Moon shadow

The Sun albedo of Cosmic Rays (CRs) at GeVs energy has been discovered recently by the FERMI satellite. They are traces of atmospheric CRs hitting solar atmosphere and reflecting skimming gamma photons. Even if relevant for astrophysics, as being a trace of atmospheric solar CR noises they cannot offer any signal of neutrino astronomy. On the contrary, the Moon with no atmosphere, may become soon a novel filtering calorimeter and an amplifier of energetic muon astronomical neutrinos (at TeV up to hundred TeVs energy); these lepton tracks leave an imprint in their beta decay while in flight to Earth. Their TeV electron air-shower are among the main signals. Also, a more energetic, but more rare, PeV up to EeV tau lunar neutrino events may be escaping as a tau lepton from the Moon: τ PeV secondaries, then, may be shining on Earth’s atmosphere in lunar shadows in a surprising way. One or a few gamma air-shower events inside the Moon shadows may occur each year in near future Cherenkov telescope array (CTA) o...