820 research outputs found
Muon and Tau Neutrinos Spectra from Solar Flares
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
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
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
In this paper we report test results from a prototype designed to detect
muons from horizontal air shower at large zenith angle,
. 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 . We estimated the
size of the surface array necessary to detect the shower flux of the order of
if originated by Tau Air-Showers
secondaries of GZK neutrino Tau below the horizons.Comment: 12 pages, 13 figure
Ultrahigh energy neutrino scattering onto relic light neutrinos in galactic halo as a possible source of highest energy extragalactic cosmic rays
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 s may interact with those (mainly heaviest
, and respective antineutrinos) clustered into HDM
galactic halos. UHE photons or protons, secondaries of 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 interaction probability is favoured by at least three order of
magnitude with respect to a direct 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., tens eV) neutrinos, probably of tau flavour.Comment: 25 pages, 1 figure minor corrections, updated references. In press in
AP
Possible Effects of the Existence of the 4th Generation Neutrino
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
Discovering Ultra High Energy Neutrinos by Horizontal and Upward tau Air-Showers: Evidences in Terrestrial Gamma Flashes?
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
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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