815 research outputs found

    Muon and Tau Neutrinos Spectra from Solar Flares

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    Solar neutrino flares and mixing are considered. Most power-full solar flare as the ones occurred on 23th February 1956, September 29th 1989, 28th October and on 2nd-4th November 2003 are sources of cosmic rays, X, gamma and neutrino bursts. These flares took place both on front or in the edge and in the hidden solar disk. The observed and estimated total flare energy should be a source of a prompt secondary neutrino burst originated, by proton-proton-pion production on the sun itself; a more delayed and spread neutrino flux signal arise by the solar charged flare particles reaching the terrestrial atmosphere. Our first estimates of neutrino signals in largest underground detectors hint for few events in correlation with, gamma,radio onser. Our approximated spectra for muons and taus from these rare solar eruption are shown over the most common background. The muon and tau signature is very peculiar and characteristic over electron and anti-electron neutrino fluxes. The rise of muon neutrinos will be detectable above the minimal muon threshold of 113 MeV. The rarest tau appearence will be possible only for hardest solar neutrino energies above 3.471 GeVComment: 14 pages, 4 figures, Vulcano Conference 200

    The time evolution of GRB spectra by a precessing lighthouse Gamma Jet

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    Inverse Compton Scattering (ICS) by a relativistic electron beam jet at GeV energies (emitted by a compact object as a NS, BH,...), a NSJ, onto thermal BBR photons (from a nearby stellar companion) may originate a collinear gamma jet (GJ). Due to the binary system interaction the GJ precession would blaze suddenly toward the observer leading to a GRB event. The internal GJ cone structure is ruled by relativistic kinematics into a concentric onion-like sequence of photon rings, the softer in the external boundaries, the harder in the inner cone. The pointing and the crossing of such different GJ photon rings to the detector lead to a GRB hardness spectra evolution nearly corresponding to most observed ones. Moreover expected time integral spectra are also comparable with known GRB spectra. The total energy input of tens of thousands of such NSJ in an extended galactic halo, mainly cosmic rays electrons, should be reflected into the recent observational evidence (COMPTEL) of a diffused relic extended halo. Evidences of such precessing jets are offered by the discover of galactic superluminal sources, recent HH jets, SN1987A outer rings, Hourglass Nebula, planetary Egg Nebula, GROJ1744-28 binary X-rays pulsar

    Light Nuclei solving Auger puzzles. The Cen-A imprint

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    Ultra High Energy Cosmic Rays (UHECR) map at 60 EeV have been found recently by AUGER group spreading anisotropy signatures in the sky. The result have been interpreted as a manifestation of AGN sources ejecting protons at GZK edges mostly from Super-galactic Plane. The result is surprising due to the absence of much nearer Virgo cluster. Moreover, early GZK cut off in the spectra may be better reconcile with light nuclei (than with protons). In addition a large group (nearly a dozen) of events cluster suspiciously along Cen-A. Finally, proton UHECR composition nature is in sharp disagreement with earlier AUGER claim of a heavy nuclei dominance at 40 EeV. Therefore we interpret here the signals as mostly UHECR light nuclei (He, Be, B, C, O), very possibly mostly the lightest (He,Be) ones, ejected from nearest AGN Cen-A, UHECR smeared by galactic magnetic fields, whose random vertical bending is overlapping with super-galactic arm. The eventual AUGER misunderstanding took place because of such a rare coincidence between the Super Galactic Plane (arm) and the smeared (randomized) signals from Cen-A, bent orthogonally to the Galactic fields. Our derivation verify the consistence of the random smearing angles for He, Be and B, C, O, in reasonable agreement with the AUGER main group events around Cen-A. Only few other rare events are spread elsewhere. The most collimated from Cen-A are the lightest. The most spread the heavier. Consequently Cen-A is the best candidate UHE neutrino tau observable by HEAT and AMIGA as enhanced AUGER array at tens-hundred PeV energy. This model maybe soon tested by new events clustering around the Cen-A and by composition imprint study.Comment: 4 pages, 5 figures

    Test results of a prototype designed to detect horizontal cosmic ray flux

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    In this paper we report test results from a prototype designed to detect muons from horizontal air shower at large zenith angle, 860<Θ<93086^{0}<\Theta<93^{0}. To detect horizontal tracks and their directions we select them according the muon vertical equivalent charge and we measure the time of flight with a time resolution of 800 ps. Several measurements are collected at different zenith angles. The background studies performed with two modules show that the main source is due to tracks crossing the module at the same time. The upper limit of background flux for a single twin module is estimated to be 109cm210^{-9} cm^{-2} s1s^{-1} sr1(90sr^{-1} (90%CL). We estimated the size of the surface array necessary to detect the shower flux of the order of 109cm210^{-9} cm^{-2} yr1yr^{-1} sr1sr^{-1} if originated by Tau Air-Showers secondaries of GZK neutrino Tau below the horizons.Comment: 12 pages, 13 figure

    Possible Effects of the Existence of the 4th Generation Neutrino

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    The 4th generation of fermions predicted by the phenomenology of heterotic string models can possess new strictly conserved charge, which leads, in particular, to the hypothesis of the existence of the 4th generation massive stable neutrino. The compatibility of this hypothesis with the results of underground experiment DAMA searching for weakly interactive particles of dark matter and with the EGRET measurements of galactic gamma--background at energies above 1 GeV fixes the possible mass of the 4th neutrino at the value about 50 GeV. The possibility to test the hypothesis in accelerator experiments is considered. Positron signal from the annihilation of relic massive neutrinos in the galactic halo is calculated and is shown to be accessible for planned cosmic ray experiments.Comment: 10 pages, 4 PostScript figure, Latex2

    Ultrahigh energy neutrino scattering onto relic light neutrinos in galactic halo as a possible source of highest energy extragalactic cosmic rays

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    The diffuse relic neutrinos with light mass are transparent to Ultrahigh energy (UHE) neutrinos at thousands EeV, born by photoproduction of pions by UHE protons on relic 2.73 K BBR radiation and originated in AGNs at cosmic distances. However these UHE ν\nus may interact with those (mainly heaviest νμr\nu_{\mu_r}, ντr\nu_{\tau_r} and respective antineutrinos) clustered into HDM galactic halos. UHE photons or protons, secondaries of ννr\nu\nu_r scattering, might be the final observed signature of such high-energy chain reactions and may be responsible of the highest extragalactic cosmic-ray (CR) events. The chain-reactions conversion efficiency, ramifications and energetics are considered for the October 1991 CR event at 320 EeV observed by the Fly's Eye detector in Utah. These quantities seem compatible with the distance, direction and power (observed at MeV gamma energies) of the Seyfert galaxy MCG 8-11-11. The ννr\nu\nu_r interaction probability is favoured by at least three order of magnitude with respect to a direct ν\nu scattering onto the Earth atmosphere. Therefore, it may better explain the extragalactic origin of the puzzling 320 EeV event, while offering indirect evidence of a hot dark galactic halo of light (i.e., mνm_\nu\sim tens eV) neutrinos, probably of tau flavour.Comment: 25 pages, 1 figure minor corrections, updated references. In press in AP

    Discovering Ultra High Energy Neutrinos by Horizontal and Upward tau Air-Showers: Evidences in Terrestrial Gamma Flashes?

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    Ultra high energy neutrinos UHE neutrino Tau, anti-neutrino Tau, anti-neutrino electron at PeVs, and higher energy may induce tau air-showers whose detectability is million to billion times amplified by their secondaries. We considered UHE nu_{tau}- N and UHE bar\nu_{e}- e interactions beyond mountains as a source of such horizontal amplified Tau air-showers. We also consider vertical upward UHE nu_{tau}-N interaction on Earth crust leading to UHE Tau airshowers {UPTAUS} or at the horizont edges {HORTAUS} and their beaming toward high mountains gamma, X, Cherenkov detectors on mountains. We show their detectability. We notice that such rare upward Tau air-shower, UPTAUS and HORTAUS, may hit even nearby airlines, ballons, satellite and flash them by short diluted gamma-burst at the edge of Gamma Ray Observatory (GRO) detection threshold. We suggest the identification of these events with recent discovered (BATSE) Terrestrial Gamma Flashes and we claim their probable UHE Tau by UHE nu_\tau origin. From these data approximated UHE nu_tau flux and Delta m_{nu_mu \nu_tau} lower bound are derived. Known X-gamma-{TeV} active galactic and extragalactic sources have been identified in most TGF arrival directions. Maximal EGRET activity in galactic Center overlap with maximal TGF flux. The UHECR AGASA an-isotropy at 10^{18} eV shows also possible correlations with TGF events. The unique UHECR triplet in AGASA clustering, pointing toward BL Lac 1ES0806+524, finds, within its error box, a corresponding TGF event, BATSE (Trigger 2444). Finally a partial TGF Galactic signature, combined with above correlations suggests an astrophysical tau origin of TGF events.Comment: 14 pages text, 13 Fig., 4 Tabs. Minor reductions to a compact form. Higher definition figures; 4Table; New Appendix A,B,C; Update Reference

    Signature of relic heavy stable neutrinos in underground experiments

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    Considering heavy stable neutrinos of 4th generation we calculate the relic density of such neutrinos in the Universe. Taking into account the condensation of heavy neutrinos in the Galaxy and applying the results of calculations to experimental data from underground experiments on search for WIMPs in elastic neutral current scattering on nuclei we found an exclusion region of neutrino mass 60 GeV < m < 290 GeV. The bounds obtained from present underground experiments while confirming the previous bounds derived from analysis of cosmic ray spectra are more relible ones. We discuss also the first indication of elastic scattering induced by WIMP in DAMA experiment finding a very narrow window of neutrino mass 45 GeV < m < 50 GeV compatible with the possible signal rate in the detector.Comment: 12 pages, 3 figure
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