arXiv subjects

Daniele Fargion

Publications and source records attributed to Daniele Fargion.

At least 55 records · Page 3Linked to original sources

arXiv2008

Tau air showers detectability with GLAST

We show that with GLAST there will be the possibility to detect, within the UHECR skimming at atmosphere edges, the showers generated by very high energy upward and horizontal Tau. The effective area, thanks to the large area covered by the showers at 550 Km, is less than that of AUGER, but its efficiency is comparable because the lower detection threshold and the consequent event rate may lead to a few EeV and-or few Glashow resonant signals within a decade.

astro-ph↗

arXiv2005

SUSY Resonances from UHE neutralinos in Neutrino Telescopes and in the Sky

In the Top-down scenarios, the decay of super-heavy particles (m~10^{12-16}GeV), situated in dark-matter halos not very far from our Galaxy, can explain the ultra-high-energy (UHE) cosmic-ray spectrum beyond the Griesen-Zatasepin-Kuzmin cut-off. In the MSSM, a major component of the UHE cosmic-ray flux at PeV-EeV energies could be given by the lightest neutralino χ, that is the lightest stable supersymmetric particle. Then, the signal of UHE χ's on earth might emerge over the interactions of a comparable neutrino component. We compute the event rates for the resonant production of "right" selectrons and "right" squarks in mSUGRA, when UHE neutralinos of energy larger than 10^5 GeV scatter off electrons and quarks in an earth-based detector like IceCube. When the resonant channel dominates in the total χ-e,χ-q scattering cross section, the only model parameters affecting the corresponding visible signal rates turn out to be the physical masses of the resonant right-scalar and of the lightest neutralino. We compare the expected number of supersymmetric events with the rates corresponding to the expected Glashow W resonance and to the continuum UHE ν-N scattering for realistic power-law spectra. We find that the event rate in the leptonic selectron channel is particularly promising, and can reach a few tens for a one-year exposure in IceCube. Finally, we note that UHE neutralinos at much higher energies (up to hundreds ZeV) may produce sneutrino resonances by scattering off relic neutrinos in the Local Group hot dark halo. The consequent \tildeν-burst into hadronic final states could mimic Z-burst events, although with quite smaller conversion efficiency.

hep-ph↗

arXiv2002

GRBs and the Ghost of the Fireball

Gamma Ray Burst has been widely believed in last decade to be super-explosions: the Fireball. We are argue on the contrary that GRBs (as well as Soft Gamma Repeaters SGR) are precessing Gamma Jets. We remind the list of contradiction that Fireball and its smaller galactic version, the Magnetar, have to face. In particular the existence of weak isolated X-ray precursor signal before the main Gamma Ray Burst and (rare SGR) events disagree with any explosive, one shoot, scenarios either isotropic or wide-beamed. We interpret them as earlier marginal blazing of outlying X conical Jet tails of precessing, spinning gamma Jet.

astro-ph↗

arXiv2002

Ultra High Energy Cosmic Ray and UHE Neutrino-Z Showering in Dark Halos

The Ultra High Energy Cosmic Ray (UHECR), by UHE neutrino-relic neutrino--Z showering in Hot Dark Halos (HDM), shows an energy spectra, an anisotropy following the relic neutrino masses and clustering in dark halo. The lighter are the relic neutrinos masses, the higher their corresponding Z resonance energy peaks. A twin light neutrino mass splitting may reflect into a twin Z resonance and a complex UHECR spectra modulation as a twin bump at at highest GZK energy cut-off. Each possible neutrino mass associates a characteristic dark halo size (galactic, local, super cluster) and its anisotropy due to our peculiar position within that dark matter distribution. The expected Z or WW,ZZ showering into proton-anti proton and neutron-anti neutron might correspond to peculiar clustering in observed UHECR at 10^{19}, 2 10^{19}, 4 10^{19} eV. A neutrino light HDM halo around a Mpc will allow to the UHECR neutron--anti-neutron secondary component at E_n> 10^{20} eV (due to Z decay) to arise playing a role comparable with the charged p-bar{p} ones. Their un-deflected n-bar{n} flight is shorter leading to a prompt and hard UHECR trace pointing toward the original UHECR source direction. The direct proton-antiproton pairs are split and spread by random magnetic fields into a more diluted and smeared and lower energy UHECR signal around the original source direction. Additional prompt TeVs signals by synchrotron radiation of electro-magnetic Z showering must also occur solving the Infrared-TeV cut-off. The observed hard doublet and triplets spectra, their time and space clustering already favour the rising key role of UHECR n-bar n secondaries originated by neutrino-Z tail shower.

hep-ph↗

arXiv2001

Upward and Horizontal Tau Airshowers by UHE Neutrinos

Upward and Horizontal Tau Air-showers (UPTAUS and HORTAUS) emerging from the Earth crust, mountain chains or deep plate boundaries are the most powerful signals of Ultra High Energy UHE anti neutrinos electron at PeV and neutrino and anti-neutrino tau at energies near and above 10^15-10^19 eV. The large tau Air-showers multiplicity N in secondaries N_opt =10^12 E_tau/ PeV, N_gamma= 10^8 E_tau/PeV, N_{e^- e^+}= 2 10^7 E_tau/PeV, N_mu = 3 10^5 E_tau/PeV^{0.85}, make easy their discover. UHE nu_tau, nu_tau because neutrino flavor mixing, nu_mu <--> nu_tau, should be as abundant as nu_mu, bar-nu_mu. Also bar{nu}_e, near the Glashow W resonance peak, E_bar{nu_e}= M^2_W / 2m_e = 6.3 10^{15} eV, may generate tau Air-showers. The HORTAUS may test the UHE neutrino interactions leading to additional fine-tuned test of New TeV Physics in Mountain Valleys and Earth crust horizontal edges. UPTAUS or HORTAUS, beaming toward high mountains, air-planes, ballons and satellites should flash gamma, muon, X and Cherenkov lights toward detectors. Such UPTAUS might already hit nearby satellite GRO gamma detectors flashing it by short (millisecond), hard, diluted gamma-burst at the edge of BATSE threshold. We claimed their identity with the observed BATSE 78 Terrestrial Gamma Flashes (TGF). The TGF clustering toward Galactic Center and Plane, known AGNs source strongly support their UHE Tau neutrino origin.

hep-ph↗

arXiv2001

Clustering, Anisotropy, Spectra of Ultra High Energy Cosmic Ray: Finger-prints of Relic Neutrinos Masses in Dark Halos

The Ultra High Energy Cosmic Ray UHECR, by UHE neutrino-relic neutrino Z showering in Hot Dark Halos HDM, should exhibits an energy spectra and an anisotropy reflecting (also) the relic neutrino masses and their hierarchical HDM halo clustering. A twin light neutrino mass splitting may reflect to twin Z resonance and into a complex UHECR spectra modulation, a twin bump, at the edge at highest GZK energy cut-off. Each possible neutrino mass associates a characteristic dark halo size (galactic, local, Super Cluster) and its local anisotropy due to our peculiar position within that dark matter distribution. A neutrino HDM halo around a Mpc will allow to the UHECR neutron secondary component at E_n> 10^{20} eV (due to Z decay) to arise playing a role comparable with the charged p- anti{p} ones. Their un-deflected n-anti{n} (or decayed p-anti{p}) flight is shorter leading to a prompt and hard UHECR trace pointing toward the original UHECR source direction. The direct p -anti{p} pairs are split and spread by random magnetic fields into a more diluted and smeared UHECR signal around the original source direction. TeVs signals by synchrotron radiation must also mark the Z-WW Showering. The UHE Neutrino- Z showering signatures may be already found in recent (and future) events in AGASA (and Auger) data. The observed hard doublet and triplets spectra, their time and space clustering already favour the rising key role of UHECR neutron secondaries originated by Z tail shower.

hep-ph↗

arXiv2001

Arrays is Space to detect Upward Tau and Highest Altitude Showers

Ultra High Energy, UHE, upward Tau neutrinos Tau, anti-neutrino Tau, above hundred TeVs and up to tens PeV energies, of relevant astrophysical nature, may lead to UHE Taus and consequent Up-ward Tau air-Showers {UPTAUS} after interaction on Earth crust surface. The UPTAUS discover may open a new UHE Tau Neutrino Astrophysics. A new generation of Gamma, X, optical and Radio Arrays in Space may discover, in the same Auger spirit, such up-coming Air-showers as well as an additional Tau signal: the nearly Horizontal Tau AIR-Shower {HORTAUS} originated by UHE neutrinos tau at 10^{19} eV energies arising from a thin Earth crust corona at few tens of degree below the horizons; a degree above the horizons, there should be over common diffused cosmic ray albedo, an additional High Altitudes (nearly Horizontal) Showers {HIAS}, by more common Cosmic Rays primaries at PeVs up to EeV and ZeV energies, both of hadronic or of electro-magnetic $γ$ nature. Mini-arrays detectors in high Altitude Balloons tails facing the horizons and the Earth below may also reveal both UPTAUS, and HIAS, and more rarely HORTAUS. Gamma Burst, Cherenkov flashes and rarer muons observed by high mountains peak arrays or high quota balloon array may better probe UPTAUS and HORTAUS. Present and future X-Gamma satellites as Beppo-Sax may be also able to discover HORTAUS and HIAS discovering transient events by UHE source (as the Crab) while in occultation by Earth. Because of the large shower distances and the Earth magnetic field, HIAS and HORTAUS showers will be split in a {Twin-Beams} fan-shaped wide arc, orthogonal to the terrestrial magnetic field, with a strong azimuths modulation. Gamma bursts with rare single muons or neutrons at the horizon, associated with HIAS, HORTAUS may be discovered by Glast and AMS satellite.

astro-ph↗

arXiv2001

Horizontal and Upward Tau Airshowers in Valleys from Mountains and Space: Discovering UHE Neutrinos and New Physics

Upward and horizontal tau Air-showers emerging from the Earth crust or mountain chains are the most powerful signals of Ultra High Energy UHE neutrinos nu_{tau}, barν_{tau} and bar{nu}_e at PeVs and higher energy. The multiplicity in tau Air-showers secondary particles, N_{opt}=10^{12}(E_{tau}/PeV), N_{gamma}= 10^8*E_{tau}/PeV, N_{e^- e^+}= 2*10^7 E_{tau}/PeV, N_{mu}= 3 *10^5 (E_{tau}/PeV)^{0.85} make easy their discover. UHE nu_tau,barν_tau, following Super Kamiokande evidence of neutrino flavor mixing, nu_mu<-->nu_tau, should be as abundant as nu_mu, barν_mu. Also anti-neutrino electrons, barν_e, near the Glashow W resonance energy peak, E_{barν_e} = M^2_W / 2m_e = 6.3*10^{15} eV may generate tau Air-showers. Upward UHE nu_tau- N interaction on Earth crust at horizontal edge and from below, their consequent upward UHE tau air-showers beaming toward high mountains, air-planes, ballons and satellites should flash gamma, mu, X and Cherenkov lights toward detectors. Such upward tau air-shower may already hit nearby satellite GRO gamma detectors flashing them by short, hard, diluted gamma-burst at the edge of BATSE threshold. The tau air-shower may test the UHE neutrino interactions leading to additional fine-tuned test of New TeV Physics both in Mountain Valleys and in Upward showers.

astro-ph↗

arXiv2001

X Ray Precursors in SGRs: Precessing Gamma Jet Tails

Weak isolated X-ray precursor events before the main Gamma Ray Burst, GRB, and also rare Soft Gamma Repeaters, SGR, events are in complete disagreement with any Fireball, or Magnetar, one-shoot explosive scenarios. Fireball model in last two years has been deeply modified into a fountain beamed Jet exploding and interacting on external shells to explain GRB fine time structure. On the contrary earlier we proposed a unified scenario for both GRBs-SGRs where a precessing Gamma Jet (of different intensity) and its geometrical beaming is the source of both GRB and SGRs wide morphology. GRBs are peaked SNs Jet spinning and precessing observed along the thin Jet axis. Their mysterious weak X precursors bursts, corresponding to non-negligible energy powers, up to million Supernova ones for GRB, are gamma Jet tails beamed off-axis, observed at X-Ray tails. They are rare, about (3-6)% of all GRBs, but not unique at all. Comparable brief X-ray precursor flashes occurred in rarest and most detailed SGRs events as the 27 and the 29 August 1998 event from SGR 1900+14. The same source has been in very power-full activity on recent 18 April 2001 once again preceded by X-Ray precursors. These events are inconsistent with any Fireball or Magnetar-Mini-Fireball models. We interpret them naturally as earlier marginal blazing of outlying X conical precessing Jet, an off-axis tails surrounding a narrower gamma precessing Jet. Only when the light-house Jet is in on-axis blazing mode toward the Earth we observe the harder power-full SGR event. We predict such a rich X-Ray precursor signals (more numerous then gamma ones) during Soft Gamma Repeater peak activities; they should be abundant and within detection threshold by a permanent monitoring SGRs by Beppo-Sax WFC or Chandra X ray satellites while at peak activity.

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arXiv2001

GRBs, Fireballs and Precessing Gamma Jets

Fireballs are huge isotropic explosions models widely believed to explain Gamma Ray Burst, GRBs (Piran,1999); ever-new versions consider wide beamed (10^o) Jet explosions hitting external shells. On the contrary, since 1994-1998, we argued (Fargion 1995-2000; see also Blackman et all.1996) that GRBs (as well as Soft Gamma Repeaters SGR) are spinning and precessing Gamma Jets, produced by collimated e^+,e^- Jet via Inverse Compton Scattering, in a very narrow (0.1^o) angles, blazing and flashing the observer. The Jet arises in Super-Nova (SN) explosions; its energy decays slowly from earliest SN powers (corresponding to GRB) toward lower stable power as Soft Gamma Repeaters (SGR) regimes. GRBs and SGRs shared (sometimes) same spectra and time structure: then SGRs are low-power GRBs, but without SN relics (or GRB afterglows, signatures of Jets in SN-GRBs). Moreover weak isolated X-ray precursor signals,(such as GRB980519, GRB981226,GRB000131), corresponding to huge isotropic, sim 10^{47} erg s^{-1}, followed by the extreme GRB, sim {10^{52}} erg s^{-1} powers, disagree with any Fireball explosive scenarios. We naturally interpret these X-Ray precursors as rare earliest marginal blazes of outlying X conical precessing Jet tails, surrounding the gamma Jet, later hitting in-axis as a GRB.

astro-ph↗

arXiv2001

Tau Air-Showers Signature of Ultra High Energy Neutrinos

The discover of Ultra High Energy Neutrino of astrophysical nature may be already reached. Indeed upward and horizontal tau Air-showers emerging from the Earth crust or mountain chains offer the best and most powerful signal of Ultra High Energy UHE neutrinos nu_tau}, barν_tau and barν_e at PeV and higher energy. The multiplicity in tau Air-showers secondary particles,N_{opt} =10^{12}, (E_tau}/ PeV, N_γ= 10^8 E_tau/ PeV, N_{e^- e^+}= 2 10^7 E_tau/PeV, N_mu =3 10^5 (E_tau/PeV)^{0.85}, make easy its over-amplified discover. Indeed UHE nu_tau, following Super Kamiokande evidence of neutrino flavour mixing, should be as abundant as nu_mu. Also anti-neutrino electrons, barν_e, near the Glashow W resonance peak, E_{\bar{ν_e}} = M^2_W / 2m_e, may generate tau Air-showers. Such horizontal tau air-showers by nu_τ-N and UHE barν_{e}-e at PeVs emerging from mountain high chain is one of the most power-full UHE neutrino imprint. Upward UHE nu_τ- N interaction on Earth crust at horizontal edge and from below, their consequent UHE tau air-showers beaming toward high mountains should flash gamma,mu,X and Cherenkov lights toward detectors located on the top of the mountains or on balloons. Such upward tau air-shower may hit also nearby satellite flashing them by short, hard, diluted gamma-burst at the edge of most sensitive Gamma Ray Observatory BATSE threshold. We identify already these rarest gamma events with recent (1994) discovered upward Terrestrial Gamma Flashes (TGF); we show their very probable UHE tau-UHE ν_τorigin. Partial TGF Galactic signature and known galactic and extra-galactic source location are discovered within known 47 TGF events at low, 2 10^{-3}, probability threshold.

astro-ph↗

arXiv2000

X Ray Precursors in GRBs and SGRs: outer X tails around a Precessing Gamma Jet

Weak isolated X-ray precursor events before the main Gamma Ray Burst, GRB, and also rare Soft Gamma Repeaters, SGR, events are in disagreement with any Fireball, or Magnetar, scenarios. These models are originated by an unique explosive event leading, by internal-external shock waves, to softer secondary trains following a main gamma signals. Indeed the earliest GRB980519,GRB981226 events as well as the latest and most distant identified one as GRB000131 are showing rare but well identified and distinct X Ray precursor, occurring tens of seconds or even a minute before the main GRB eruption. These weak X precursors bursts correspond to non-negligible energy powers, up to million Supernova ones. They are rare, about (3-6)% of all GRBs, but not unique. Similar huge explosive precursor are in total disagreement with a successive main Fireball GRB outburst. Comparable brief X-ray precursor flashes are found also in rarest and most detailed SGRs events as those observed on 27 and 29 August 1999 from SGR 1900+14. They are inconsistent with a Magnetar Fireball explosion. We interpret them as earlier marginal blazing of outlying X conical Jet tails surrounding a narrower gamma precessing,spinning beamed Jet in blazing mode toward the Earth; later re-crossing and better hitting of the target -the satellite detectors- is source of the main GRB (and SGR) observed structured event. The X Ray precursor existence is an additional remarkable evidence of the Precessing relativistic Jet Nature of both GRBs and SGRs.

astro-ph↗

arXiv2000

Detecting Ultra High Energy Neutrinos by Upward Tau Airshowers and Gamma Flashes

Tau Air-showers are the best trace of rarest Ultra High Energy neutrinos UHE $ν_τ$, $\barν_τ$ and $\barν_e$ at PeV and higher energy. $τ$ Air-showers may generate billion times amplified signals by their secondaries . Horizontal amplified $τ$ air-showers by $ν_τ N$ and UHE $\barν_{e} e$ at PeV emerging from mountain chain might be the most power-full imprint. Upward UHE $ν_τ N$ interaction on Earth crust at horizontal edge and from below, their consequent UHE $τ$ air-showers beaming toward high mountains should flash $γ$,$μ$,X and optical detectors on the top. Upward $τ$ air-shower may hit nearby satellite flashing them by short, hard, diluted $γ-$burst at the edge of Gamma Ray Observatory BATSE threshold. We identify these events with recent (1994) discovered upward Terrestrial Gamma Flashes (TGF) and we probed their UHE $τ$ - UHE $ν_τ$ origin. From these TGF data approximated UHE $ν_τ$ flux and $Δm_{ν_μν_τ}$ sever lower bound are derived. Partial TGF Galactic signature is also manifest within known 47 TGF events clustered within three degrees from the Galactic plane at ${\simeq 2\cdot 10^{-3}}$probability. Well known $X-γ-\mathrm{TeV}$ active galactic and extragalactic sources have found probable counterpart in TGF arrival directions. Detection of elusive UHE $ν_τ$ seem finally achieved.

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arXiv1999

Giant Stellar Arcs as the imprint of Precessing Gamma Jets by Gamma-Ray Bursts

Precessing Gamma Jets, originated by Neutron Stars or Black Holes, may blaze to the observer leading to Gamma Bursts (GRBs) and Soft Gamma repeaters (SGRs). The thin gamma jet is born either at Supernova (SN) like events mostly at the cosmological distances, like GRB, or at nearer accreting binary system, like SGRs. The collimated gamma jet Comptonized by the ultrarelativistic inner electron pairs jets (hitting thermal photos) spins (because of the pulsar) and precedes (because of a companion or accreating disk) in helical and spiral nebular shapes. Its cumulative spray may eject and sweep gas creating nebular rings and plerions and, after long time, partiall HI supershells. Their consequent gravitational fragmentation may lead to characteristic star formation in giant arcs, which might be just the relic imprints of the earliest peaked GRBs and the late steady SGRs precesing jet emissions. Relic stellar rings and arcs may inform, by present morphology on the jet binary eccentricity and its time evolution. Their lifetime and occurrence may probe the Supernova-GRB connection.

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arXiv1999

Galactic Gamma Halo by Heavy Neutrino annihilations?

The diffused gamma halo around our Galaxy recently discovered by EGRET could be produced by annihilations of relic neutrinos N (of fourth generation), whose mass is within a narrow range (Mz /2 < M < Mz). Neutrino annihilations in the halo may lead to either ultrarelativistic electron pairs whose inverse Compton Scattering on infrared or optical galactic photons could be the source of the observed GeV gamma rays, or to prompt 100 MeV- 1 GeV photons (due to neutral pion secondaries) born by N - anti N --> Z--> quark pairs reactions. The consequent gamma flux (10 ^(-7)- 10^(-6) cm ^(-2) s^(-1) sr^(-1)) is well comparable to the EGRET observed one and it is also compatible with the narrow window of neutrino mass : 45 GeV < M < 50 GeV recently required to explain the underground DAMA signals. The presence of heavy neutrinos of fourth generation do not contribute much to solve the dark matter problem of the Universe, but it may be easily detectable by outcoming LEP II data.

astro-ph↗

arXiv1999

Gamma Ray Burst and Soft Gamma Repeaters. Spinning, Precessing Gamma Jets

Gamma Ray Bursts as recent GRB990123 and GRB990510 are observed to occur in cosmic volumes with a corresponding output reaching, for isotropic explosions, energies as large as two solar masses annihilation. These energies are underestimated because of the neglected role of comparable ejected neutrinos bursts. These extreme power cannot be explained with any standard spherically symmetric Fireball model. A too heavy black hole or Star would be unable to coexist with the shortest millisecond time structure of Gamma ray Burst. Beaming of the gamma radiation may overcome the energy puzzle. However any mild explosive beam $(Ω> 10^{-2})$ should not solve the jet containment at those disruptive energies. Only extreme beaming $(Ω< 10^{-8})$, by a slow decaying, but long-lived precessing jet, it may coexist with characteristic Supernova energies, apparent GRBs output, statistics as well as their connection with older and nearer SGRs relics.

astro-ph↗

arXiv1999

Horizontal Tau air showers from mountains in deep valley. Traces of UHECR neutrino tau

Ultra High Energy (UHE) Tau neutrino may lead to a very peculiar imprint in future underground $Km^3$ detectors in water and ice as well as in air: rarest secondary tau tracks and decay which may exceed the muon ones. Indeed Bremsstrahlung at high energy lead to longer tracks for heavier leptons. Radiation lenght grows nearly with the square of the lepton mass. Indeed electrons are too light and their trace in matter (liquid or rock) is negligible (tens of centimeters); muons are much better observed, while tau are too short life time and too short range to be found. However, because relativistic time expansion, UHE tau traces in matter, above $10^{17} eV$, are relativistically boosted overcoming the corresponding muon tracks, already bounded by bremsstrahlung logarithmic regime. The tau crossing for Kms in water or ice may be confused with common muon tracks; their tau decay may be misunderstood as muonic catastrophic bremsstrahlung interactions. To economize UHE tau discovery, we suggest to look the tau decay in air into the deep valleys mountains, like Canyons or deep in excavation mines where horizontal air showers induce fluorescent or Cerenkov lights. The mountain valley width screens from horizontal secondary muons. The valley height increases the solid angle view. The horizontal air Kms-size gap offer a strong discriminator to filter UHE muons against tau. Tens event a year at PeV (W resonance peak) energies in $Km^3$ excavation gap should be observable . Hunting air shower in the night toward high mountains in Canyons or in a deep excavation may be the best and cheapest way to discover UHE neutrinos, either born by electron anti neutrino scattering on electrons at PeV energies, or by direct tau neutrino possibly relic of muonic flavour oscillation even at EeV energies.

astro-ph↗

arXiv1999

Ultrahigh energy neutrinos scattering off relic light neutrinos to explain UHECR above GZK cut off and thin blazars

UHE neutrinos may transfer highest cosmic-rays energies overcoming $2.75K^\circ$ BBR and radio-waves opacities (the GZK cut off) from most distant AGN sources at the age of the Universe. These UHE $ν$ might scatter onto those (light and cosmological) relic neutrinos clustered around our galactic halo or nearby neutrino hot dark halo clustered around the AGN blazar and its jets. The branched chain reactions from a primordial nucleon (via photo production 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); its corresponding UHE radiation power is in agreement with the observed one in MeV gamma energies. The final chain products observed on Earth by the Fly's Eye and AGASA detectors might be mainly neutron and anti-neutrons and delayed, protons and anti-protons at symmetric off-axis angles. These hadronic products are most probably secondaries of $W^+ W^-$ or $ZZ$ pair productions and might be consistent with the last AGASA discoveries of doublets and one triplet event.

astro-ph↗