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D. Fargion

Publications and source records attributed to D. Fargion.

At least 91 records · Page 5Linked to original sources
arXiv2002

Ultra high-energy neutrino at GZK energy: Z-WW showering in dark halo and tau airshowers emerging from the Earth

Relic neutrino nu_r light masses clustering in Galactic and Local Hot Dark Halos act as a beam dump calorimeter. Ultra High Energy nu, above ZeV, born by AGNs, GRBs at cosmic edges, overcoming (GZK) cut-off, may hit near Z resonance and WW-ZZ channels energies: their showering into UHECR fit observed data . Any tiny neutrino mass splitting may reflect into a twin bump at highest GZK energy cut-off. The Z or WW,ZZ showering explain a peculiar clustering in observed UHECR spectra at 10^19, 210^19, 4 10^19 eV found by AGASA. Coincidence of clustered UHECR with highest gamma BLac sources is well tuned to Z-Showering Scenario. Additional prompt TeVs signals occur offering a natural solution of growing Infrared-TeV cut-off paradoxes related to distant TeV BLac sources and a GRB at TeV energy. Electromagnetic Cascades tail explain correlation found between GeV-EGRET Sources and UHECR. Such UHE nu Astrophysics might trace into Horizontal Tau Air-Showers originated by the UHE nu_tau Earth-Skimming in wide Corona Earth Crust around the observer. These Upward and Horizontal tau Air-Showers UPTAUS, HORTAUS, monitor huge volumes from high mountains as well as observing from planes, balloons and satellites. HORTAUS from mountains observe corona masses at UHE neutrino at EeVs energies comparable to few km^3, while from satellites at orbit altitudes, at GZK energies, their corresponding Horizontal Corona Masses may even exceed 150 km^3. The expected event rate may exceed a dozen of event a year in Z-WW Showering model from satellite.

hep-ph↗
arXiv2002

Antimatter Bounds by Anti-Asteroids annihilations on Planets and Sun

The existence of antimatter stars in the Galaxy as possible signature for inflationary models with non-homogeneous baryo-synthesis may leave the trace by antimatter cosmic rays as well as by their secondaries (anti-planets and anti-meteorites) diffused bodies in our galactic halo. The anti-meteorite flux may leave its explosive gamma signature by colliding on lunar soil as well as on terrestrial, jovian and solar atmospheres. However the propagation in galaxy and the consequent evaporation in galactic matter gas suppress the lightest (m < 10^(-2)g) anti-meteorites. Anisotropic annihilation of larger anti-meteorites within a narrow mass window, maybe rarely deflected, bounced by the galactic gas disk, escaping detection in our solar system. Nevertheless heaviest anti-meteorites (m > 10^(-1)g up to 10^(6)g) are unable to be deflected by the thin galactic gas surface annihilation; they might hit the Sun (or rarely Jupiter) leading to an explosive gamma event and a spectacular track with a bouncing and even a propelling annihilation on cromosphere and photosphere. Their anti-nuclei annihilation in pions and their final hard gammas showering may be observabe as a "solar flare" at a rate nearly comparable to the observed ones. From their absence we may infer bounds on antimatter-matter ratio near or below 10^(-9) limit: already recorded data in BATSE catalog might be applied.

hep-ph↗
arXiv2001

Time Delay Between Gravitational Waves and Neutrino Burst From a Supernova Explosion: a Test for the Neutrino Mass

During Supernova explosions two signals, Gravitational burst wave and Neutrino Burst, of different nature, originated within 0.1 s from thesuper nova explosion will be radiated in the outer space. If the neutrinos (as well as the gravitons) are massless particles, than the original interval (if any) between the two signals will be freezed forever. On the contrary, if the neutrinos have a tiny mass, the time delay will increase during the propagation because of the slower velocity of the neutrinos with respect to the massless gravitons. Therefore, two signals, of different nature, originated within 0.1 s from the super nova explosion will be radiated in the outer space. If the neutrinos (as well as the gravitons) are massless particles, than the original interval (if any) between the two signals will be freezed forever. If the neutrino has a mass the time delay will increase during the propagation because of the slower velocity of the neutrinos with respect to the massless gravitons: the time delay detection may measure the neutrino mass or its absence may inferr a severe neutrino mass bound.

hep-ph↗
arXiv2001

Ultra High Energy Neutrino-Relic Neutrino Interactions In Dark Halos to Solve Infrared-Tev And GZK Cut-Off

Ultra High Energy Neutrino scattering on Relic Light Neutrinos in Dark Galactic or Local Group lead to Z and WW,ZZ showering: the nucleon component of the shower may overcome the GZK cut-off while the electro-magnetic tail at TeVs up to EeVs energy may solve the Infrared-TeV cut-off in a natural way. Different Gamma TeV puzzles may find a solution within this scenario: new predictions on UHECR spectra in future data are derived.

astro-ph↗
arXiv2001

Gravitational Shapiro Telescope on the PSR's period to discover Dark Planets and Machos

Collective Shapiro Phase Shift on the period of the pulsars due to a dark object (a passing MACHO or a planet) along the line-of-sight of one or more pulsar is a formidable gravitational tool to discover dark matter.We already noted that the presence of a few negative PSRs period, possibly due to such a Shapiro delay, is roughly consistent with independent estimates of MACHOs observed by microlensing in our Galaxy. Here we update our study and suggest to verify and to calibrate the Shapiro phase delay to observe on ecliptic main known planetary and solar gravitational fields. Once the test is probed we propose to use, in a collective way, a subsample of PSRs on the ecliptic plane to monitor our solar system for discovering any heavy unknown object, either dark Macho or planets. The importance of such unknown possible planetary components and their eventual near encounter with Earth in the far past (or future) should be not neglected : the same life evolution (or extinction) might be marked by such a rare event.

astro-ph↗
arXiv2001

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_{ν_{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_{ν_{SK}}}/m_ν10^{21}),eV. Other shadowsof lightest, nearly massless, neutrinos m_{nu_{2K} simeq 0.001eV simeq kT_ν, 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_{ν_{2K}/E_ν})10^{23}, eV .

astro-ph↗
arXiv1999

Quantum Mach effect by Sagnac Phase Shift on Cooper pairs in rf-SQUID

The inertial drag on Cooper pairs in a rotating rf-SQUID ring leads to an asymmetry in the Hamiltonian potential able to force the average magnetic field versus in the ring along the angular velocity one. This effect is a Sagnac signature of Cooper pairs at a quantum level and it may probe the fundamental quantum Mach principle within detectability levels.

astro-ph↗
arXiv1999

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.

astro-ph↗
arXiv1999

Scattering of Ultrahigh Energy (UHE) Extragalactic Neutrinos onto Light Relic Neutrinos in Galactic HDM Halo Overcoming the GZK Cut off

The rarest cosmic rays above the GZK cut'off $(E_{CR} \tilde{>} 10^{19} ÷10^{20} eV)$ are probably born at cosmic distances ($\tilde{>}$ tens Mpc) by AGNs (QSRs, BLac, Blazars...). Their puzzling survival over $2.75 K^o$ BBR radio waves opacities (the ``GZK cut off'') might find a natural explanation if the traveling primordial cosmic rays were UHE neutrinos (born by UHE photopion decay) which are transparent to $γ$ or $ν$ BBR. These UHE$% ν$ might scatter onto those (light and cosmological) relic neutrinos clustered around our galactic halo. The branched chain reactions from a primordial nucleon (via photoproduction of pions and decay to UHE neutrinos) toward the consequent beam dump scattering on galactic relic neutrinos is at least three order of magnitude more efficient than any known neutrino interactions with Earth atmosphere or direct nucleon propagation. Therefore the rarest cosmic rays (as the 320 EeV event) might be originated at far $(\tilde{>} 100 Mpc)$ distances (as Seyfert galaxy MCG 8-11-11). The needed UHE radiation power is in rough agreement with the NCG 8-11-11 observed in MeV gamma energy total output power. The final chain products observed on Earth by the Fly's Eye detector might be mainly neutron and antineutrons as well as, at later stages, protons and antiprotons. These hadronic products are most probably secondaries of $W^+ W^-$ or $ZZ$ pair productions and might be consistent with the last AGASA discoveries of 6 doublet and one triplet event.

astro-ph↗
arXiv1999

On the Heavy Relic Neutrino - Galactic Gamma Halo Connection

A halo model with heavy relic neutrinos N belonging to a fourth generation and their annihilations in galactic halo may explain the recent evidence of diffused gamma (GeV) radiation around galactic plane. We considered a neutrino mass in the narrow range ($M_Z/2 < m_N < M_Z$) and two main processes as source of gamma rays. A first one is ICS of ultrarelativistic electron pair on IR and optical galactic photons and a second due to prompt gammas by $π^0$ decay, leading to a gamma flux ($10^{-7} - 10^{-6} /(cm^2 s sr)$) comparable to EGRET detection. Our predictions are also compatible with the narrow window of neutrino mass $45 GeV < m_N < 60 GeV$, required to explain the recent underground DAMA positive signals.

astro-ph↗
arXiv1998

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 $ν$s may interact with those (mainly heaviest $ν_{μ_r}$, $ν_{τ_r}$ and respective antineutrinos) clustered into HDM galactic halos. UHE photons or protons, secondaries of $νν_r$ 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 $νν_r$ interaction probability is favoured by at least three order of magnitude with respect to a direct $ν$ 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., $m_ν\sim$ tens eV) neutrinos, probably of tau flavour.

astro-ph↗
arXiv1998

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.

astro-ph↗
arXiv1997

The role of ν_τ ultrahigh energy astrophysics in Km^3 detectors

We show that the expected $ ν_τ $ signals, by their secondary tau tracks, in Km^3 detectors at highest cosmic ray energy window $ 1.7\cdot 10^{21} eV \gt E_τ \gt 1.6 x 10^{17} eV$, must overcome the corresponding $ ν_μ $ (or muonic) ones. Indeed, the Lorentz-boosted tau range length grows (linearly) above muon range, for $ E_τ \RAISE 1.6 x 10^8 GeV$ and reaches its maxima extension, $ R_{τ_{\max}} \simeq 191 km$, at energy $E_τ \simeq 3.8 x 10^9 GeV$. At this peak the tau range is nearly 20 times the corresponding muon range (at the same energy) implying a similar ratio in $ ν_τ $ over $ ν_μ $ detectability. This dominance, however may lead (at present most abundant $ ν_τ $ model fluxes) to just a rare spectacular event a year (if flavor mixing occurs). Lower energetic $ τ$ and $ ν_τ $ signals $ (\barν_e e\to \barν_τ τ, ν_τ N\to ...) $ at energy range ($ 10^5 ÷10^7 GeV$) may be more easily observed in km^3 detectors at a rate of a few $ (\barν_e e\to \barν_τ τ) $ to tens event $ (ν_τ N\to τ+ $ anything) a year.

astro-ph↗
arXiv1996

Inverse Compton Scattering on laser beam and monochromatic isotropic radiation

Most of the known literature on Inverse Compton Scattering (ICS) is based on earliest theoretical attempts and later approximations led by F.C.Jones and J.B.Blumenthal. We found an independent and more general analytical procedure which provide both relativistic and ultrarelativistic limits for ICS. These new analytical expressions can be derived in a straightforward way and they contain the previously reminded Jones' results. Our detailed solutions may be probed by already existing as well future ICS experiments.

astro-ph↗
arXiv1996

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.

astro-ph↗
arXiv1996

Precessing Gamma Jets in extended and evaporating galactic halo as a source of GRB

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.

astro-ph↗