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arXiv:0905.1517v1 [astro-ph.HE] 10 May 2009
ACHIEVEMENTS AND MIRAGES in UHECR and NEUTRINO
ASTRONOMY
D.Fargion, D. D’Armiento
Physics Department and INFN, Rome University 1, Sapienza, Address
Ple A. Moro 2, 00185, Rome. Italy
E-mail: daniele.fargion@roma1.infn.it
ABSTRACT
Photon Astronomy ruled the last four centuries while wider photon band ruled
last century of discovery. Present decade may see the rise and competition of
UHECR and UHE Neutrino Astronomy. Tau Neutrino may win and be the first
flavor revealed. It could soon rise at horizons in AUGER at EeV energies, if
nucleons are the main UHECR currier. If on the contrary UHECR are Lightest
nuclei (He, Li. B) UHE tau neutrino maybe suppressed at EeV and enhanced
at tens -hundred PeV. Detectable in AMIGA and HEAT denser sub-array in
AUGER. Within a few years.
1. Introduction: UHECR versus UHE neutrino Astronomy
Galileo four century ago invented large lens telescopes for an amplified view of the
stars. Its strategy ruled and rules optical Astronomy. More photon telescopes in wider
spectra, from largest radio antenna to space X-gamma satellite, extended our views
last century in Maxwell regimes. However at hundred TeVs photons hit abundant
relic cosmic photons making electron pairs. This opacity leads to a very bounded tens
TeVs gamma Astronomy almost galactic at PeV energy band. Cosmic Rays offer an
energetically flux comparable to photon ones but they are charged and bent by cosmic
magnetic fields. Therefore CR astrophysics is blurred and blind. UHECR are as much
as energetic to offer a straight view of the source and a novel Astronomy. But also
UHECR at GZK cut off (tens EeV energy) are bounded in a very Local Universe too.
As small as 1% radius and a part of a million of the volume. First spectra and maps
of AUGER UHECR seemed to see the first Super-Galactic shadows, or maybe as we
critically noted, just their mirages formed by the main Cen-A spread events, as a
main blurred source in AUGER map. Virgo absence is obvious by He-Li-Be opacity
beyond 10 Mpc. The same UHECR GZK secondary, the cosmogenic neutrinos are
neutral and are tracing, with no photon-like opacity, wider cosmic spaces. Better
and deeper tracing explosive or Jet source. This push most to call for UHE Neutrino
Astronomy. Electron neutrino are ruling only at few-tens-hundred MeV. GeVs muons
are more penetrating and better detectable. The muon neutrino search above tens-
hundreds GeV, implemented in km cube ice or water underground, is already four
decade old. Its records are slowly growing now, finally reaching this year its dreamt
performance. This is a great achievements of the decade. But muon neutrinos are
Figure 1: The Cosmic Radiations: the lower energy left side spectra mostly describe photons. Higher
energy (above TeVs) radiations on right side are describing the charged Cosmic ray contribute. At
these high energies (TeVs-PeVs) photons are scattering onto Infra-red, optics and BBR ones, making
opaque far cosmic sources. Similar energetic neutrinos are transparent to such photons. However
at Earth both electron and muon neutrinos suffer of the secondary atmospheric noise. Tau are well
produced by oscillation (shown above in logarithmic fashion). The higher the energy, the less the
oscillation. At TeV energies tau neutrinos are almost absent because the small Earth size respect to
the neutrino-mass oscillation length. This make tau neutrino noise free, but very short and hard to
observe, at TeVs. However at PeVs-EeVs energies the tau track are more and more long and rising
deeper from matter below. Their later decay in flight is better amplified and disentangled from any
(absent) hadron air-shower at horizons. An inclined line marked Waxmann Bachall (WB) label the
minimal energy (at Tens EeV) fluency in CR. Incidentally comparable to GRB main fluency. This is
the minimal fluency of PeVs-EeVs neutrinos in the Sky.If UHECR are not nucleons EeV neutrinos
may be less present,their flux may escape as a mirage. See Last Figures
polluted vertically by a noisy atmospheric neutrino background. At less polluted
higher energy UHE νµare suppressed by Earth Opacity. At horizons, while the Earth
cord is shorter and less opaque to UHE neutrinos, the prompt atmospheric neutrinos
νµ,νeare more abundant, by at least an order of magnitude, than vertical ones.
Making a even more noisy the sky to νµ,νe. On the other side the tau Neutrino
Astronomy invented only a decade ago, is much more silent and quite. Indeed it
is already competing with the muon one via AUGER bounds, reaching AMANDA
and maybe ICECUBE. Tau are extremely difficult to be produced. But the muon
neutrino flavor mixing induce and rise their rare flavor. But the oscillation do not
occur in Earth size above tens GeV. The ντare the neutral lepton of the heaviest and
most unstable charged τ. Such a Ultra High Energy (UHE) tau born after neutrino
skimming and interacting on the Earth skin may lead, once in air, to Tau Air-shower.
A huge amplified explosion in air. Spraying over huge area huge number of secondary
particles. Possibly the first Neutrino Astronomy to be discovered. Because of the
severe Earth opacity, EeV neutrinos grow at best at horizons (short cord) below the
horizons. There are no rich hadrons air-shower filtered at horizons or even below. The
ντsky lay beyond the mountains chains or under our feet 4). Mostly in AUGER area,
as the wide nearby Ande screen. Energetic Tau neutrinos above TeV energy are noise
free respect overabundant atmospheric muon neutrino. But taus at TeVs are short
in matter and rare to emerge. Their skimming Earth at PeVs-EeVs energy and the
consequent tau decay in air offer however an unique neutrino air-showering upward-
horizontal, at low atmosphere (1 −8 km) , in a few km deep and few microsecond
long track; they differ drastically from hadronic tangent air-showers blowing only at
very high (25-35) km diluted altitude. Such hadron air-shower are very thin, lengthy
(hundreds km) and longevous showers. Difficult (or impossible) to observe in AUGER
Fluorescence Detector. The hadron air-shower beams are often split by geomagnetic
fields. Therefore the Fluorescence detection of upward EeV Tau air-shower is at hand
(this or next years) in largest fluorescence telescope array as AUGER, if UHECR are
mostly nucleons. However UHECR maps and their observed composition puzzle us.
They forced us to imagine UHECR as the lightest nuclei : their consequent UHECR
GZK secondary neutrinos, are only partially born (half a number) in photo-pion.
Their secondary neutrinos must be mostly by nuclear fragmentation within a very
Local Universe (Cen-A being the main source at 4 Mpc). These UHECR processes
are making fewer GZK neutrinos than expected at EeV, reducing as in a mirage their
detection goal. More abundant signals at tens-hundred PeV energy must nevertheless
rise. These UHE PeVs tau neutrinos might be revealed better in a new inner and
denser array of AUGER, the HEAT and AMIGA, tuned to lower energies. Or in
competition within new born ICE-CUBE km detector mostly via UHE lengthy muons
(if disentangled by UHE prompt neutrinos). Double bang may also rise. We foresee
them to be found soon, within a few years (3-4), in a very peculiar and marked
imprint in AUGER-HEAT-AMIGA array. Possibly tracing the resonant Glashow
anti-neutrino electron.
2. New Neutral Particle Telescopes?
Look at the blue sky in day time: no star are visible in diffused sun lights. To see
stars one must look at dark nights. This remind us that a signal shine at best in a
noise free screen. To better reveal any weak signal also amplifiers are needed. Optical
photons (mostly linked to sun spectra) forced astronomers on top altitude observato-
ries. Galileo used the lens not just for a sharper view but also for an amplified one.
Photons are neutral and they flight along a direct line. Offering a clear view. Cosmic
Rays, as rich as other cosmic fluency are charged ones. They suffer of bending and
blurring along the cosmic (Earth, Sun, Galactic, intergalactic) magnetic fields. The
same existence of large magnetic fields stand and remind us a neglected cosmic puzzle:
the (apparent) absence of any magnetic monopole as cosmic relic trace. Photons are
not the unique neutral particles: also neutrons and antineutrons and gravitons are
well known neutral particles. Indeed Solar flare (Compton Observatory,OSSE,1991)
shine GeVs neutrons at largest solar flares. PeV Neutrons may also rise from ten
parsec nearest pulsars. EeV neutrons may survive even from our galactic center. A
decade ago such an anisotropy was revealed and claimed from AGASA, but it has
been disproved by later AUGER records. Tens-hundred EeV neutrons may rise by
GZK secondaries even from nearest extragalactic sources (Mpc distance). Antineu-
trons are much rarer: possibly born in a very speculative anti-galaxy via anti GZK
secondaries. Finally gravitons may also tremble in detectors as soon as a Supernova
shine in nearby universe. But at the present with little angular resolution. Finally
speculative UHE neutralinos might shine if SUSY occurs and if it plays a compa-
rable role in UHECR components. Apart these four neutral candidates, there are
other guaranteed ones to be revealed. Neutrino Astronomy is not just one, but as
their lepton flavors they are three or better because anti-matter states, the neutrino
astronomy are six.
3. Six Neutrinos Astronomy: Virtues and Defects
Electron are the lightest leptons and the easiest to observe because of the low mass
threshold. Inverse beta decay is a key processes. The nuclear plant were their first
sources laboratory. The shining overabundant Solar neutrino astronomy has been
revealed last decades via different detectors because their huge fluency. Supernova
1987A, even from Magellanic Cloud outside our Milky-Way, had left a tiny signals
in earliest detectors more than two decade ago. Cosmic Relic supernova (average
traces) are at the edge of detections. A new and exciting neutrino astronomy might
rise via Megaton underground detectors by largest solar flare. However at tens MeVs
and above the astrophysical neutrinos are sinking into the atmospheric secondary
sea. Their corresponding Telescopes usually lay in underground to screen the huge
polluting downward cosmic ray lepton secondaries. Their direct lepton downward
noise is nearly twelve order above any (tens GeV) neutrino signal. Moreover at high
energy electron and positron signals maybe overcome by muon ones because at GeVs
energies and above muons are more penetrable and much longer than electrons. How-
ever muon (as well electron) neutrinos suffer of the ruling CR secondary noise. The
CR secondary muons pollute abundantly the down ward vertical direction, even in
deep km underground detectors. Nevertheless also Up-going neutrinos are polluted
by the same atmospheric ones at least by three order of magnitude above expected
astrophysical sources. At tens TeV energies the astrophysical signal may finally com-
pete with the atmospheric noise. But Earth opacity rise at vertical axis. Tau are
almost absent because charmed mesons are hard to be born. However at GeVs muon
neutrino oscillate into tau ones; but above ten GeVs their energies are so high that
the oscillation cannot take place inside our Earth diameter. Therefore Tau neutrinos
above TeV are mostly of astrophysical nature with little or none mixing, just noise
free. This make them interesting. As energy increase above PeVs tau length grows
linearly while muon track grows in logarithmical law. Therefore at EeV Tau may
be longer than muon track. Moreover just above PeV energy (corresponding 50 m
tau distances) their birth first and they sudden decay after into Tau offer a very
rare signature: a double bang ( Learned and Pakwasa (1995)) imprint in water or
ice. Therefore their relevance survive and rise above PeV. At PeV-EeV energies their
bang (in the Earth) and their decay out, (in the air) offer the Tau skimming decaying
in flight, producing loud, amplified Tau air-showers. The muons searched in Cubic
km detector may be at detection edges if the UHECR are of lightest nuclei nature.
However as noted above of neutrino pollution , at horizons of prompt neutrino ones.
Tau air-showers maybe born ( one over ten) also by resonant anti-neutrino electron at
6.4 PeV energy. Therefore Tau Air-showers may be even born without Tau neutrino
at all.
4. The UHECR GZK neutrino flux and Tau expected rate
The predictions on Tau Astronomy moved fast from sceptical to a more optimistic
attitude from AUGER group, mostly via ground detectors (see figures below). On the
contrary we foresaw an event in FD within a few recent years since a few years with
stable attitude. We have been optimistic from the earliest time foreseing one event
within three years, if UHECR at WB flux was due to nucleons. However the very
possible He composition of UHECR reduce the EeV neutrino rate and correspondingly
our predictions by a factor two (at least). At lower energy there are signals at Tens
PeV observable in smaller detectors like HEAT and AMIGA and-or in FD telescope
Figure 2: The integral rate of up going Tau including the resonant neutrino contribute in three
years estimated in earlier papers. The small triangular bump due to Glashow resonant antineutrinos
scattering on electrons is mainly due to the energy spread of the tau energy at its birth. The rate
are estimated for a total AUGER area at 10% efficiency for FD. The FD threshold is growing
linearly with energy and it is respectively 300K m2, 30K m2, 3Km2at the energy E eV , 0.1EeV ,
0.01 EeV. Because of it each rate at lower energies than EeV must be suppressed in FD efficiency by
corresponding factor (0.1, 0.01) making the expected event rate at ten PeV (0.26) and hundred PeV
(0.5), just below unity in 3 years. The additional mini-array AMIGA at 27.5K m2, 6K m2, whose
array spacing is respectively 750, 433 m, is a SD active day and night and it might double the signal,
offering a detection in a very few years from now (0.35-0.4 event/year).
at nearer distances (2-3 km) to be discussed later.
5. Foreseen Hadron Air-Showering via Fluorescence and Cherenkov
Tau Air-showers rise at horizons. Therefore it is important to test inclined down-
ward hadronic air-showers. We did suggest first that the search of horizontal airshow-
ers may be implemented by flashing cherenkov photons (rich signal but beamed one)
and-or by fluorescence lights 7). The prediction of such rare inclined events observable
in both way has been offered just in earlier paper 6)and observed just a year later
by AUGER group 11). The possibility to use both signals may offer a road map to
calibrate the AUGER CR at lower energy. Indeed the Cherenkov flashes may rich
PeV energies and they may at best pointing the Ande mountain chain. Therefore our
hopes for a wild use of the AUGER and HEAT telescopes also for Cherenkov signal
is alive. The enhanced position of water-Cherenkov tanks nearby these telescopes
may help to test and increase their ability in inclined air-shower at horizons. Among
them the upgoing Tau airshowers may still shine a little downward by the soft elec-
tromagnetic tails bent by geomagnetic fields. These possibilities maybe exploited at
best toward the West (Ande) side.
Figure 3: Foreseen Inclined Horizontal Air-Showers able to trigger both Auger tanks and Fluorescence
telescopes , while being in the same axis. This technique, has never been used to better disentangle
horizontal Air-Showers. It may be an ideal detector to observe Tau Air-Showers from the Ande.
Their events will populate the forbidden area of large zenith angle at horizons. For this reason it will
be useful to: a) enlarge the angle of view of Coiuheco (as well as Loma Amarilla and Leones station)
toward the Ande; b) to eliminate any optical filter for Cherenkov lights in those directions ; c) to
open a trigger between the Array-Telescope, or Telescope-Telescope in Cherenkov blazing mode;
d) to try all 4 telescope Fluorescence connection in Cherenkov common trigger-mode along all the
6·2 = 12 common arrival directions. Similar connection along the 360oview of stereoscopic HIRES
telescopes, might be already recorded . Similar mutual use may rise in MAGIC-HESS-VERITAS
array facing their telescopes at horizons triggered by vertical downward air-showers. In the picture
some possible inclined UHECR events imagined (more than a year before the discovery) shining
both array FD detectors and (by Cherenkov lights) Fluorescence Station in AUGER; possible twin
separated ovals arise by geomagnetic bending has been partially observed.
Figure 4: As above the observed inclined air-shower as expected above to hit both at Cherenkov
and Fluorescence track an year later (2007) by the AUGER group . More details in (Fargion at all.
2007-NIM)
6. UHECR Lightest Nuclei versus UHE ν: the GZK connection
Tau decay in flight are better than neutrino interacting in air because Earth rock
density is three thousand times larger than air one. Even if the tau enjoy of a bounded
escaping solid angle (a zenith angle width of 2 −5 degree) while all down-ward neu-
trinos interacting on air may reach from wider cone (a zenith angle width 15 degree)
and are in three flavors. Such skimming events in AUGER experiment may rise via
upward tau air-shower 4),9),10). In last years the upward-horizontal EeV τ,¯τappear-
ance, via UHECR p+γCM B →π→νhas been predicted by many authors; the most
extreme ones were at rate of 0.1−0.03 a year 10), or 0.3 a year in AUGER 7)and
finally up to 0.2 a year 12). This rate, has only recently being adjusted and confirmed
by last AUGER group estimates (NOW 2008, CRIS 2008):0.3 a year, in full agree-
ment with our previous (and persistent) ones 7). The last AUGER predictions are
even overcoming our expected rate 13)even in over optimistic way. Indeed following
the AUGER evidences (and Hires ones 15)) of an UHECR GZK cut-off and the lat-
est AUGER (possible) Super-Galactic anisotropy due to an eventual proton UHECR
guarantee a secondary flux of UHE-GZK neutrino at EeVs energy within AUGER
detection via τ,¯τshowering 7). In fact this occurs because the muon neutrino fla-
vor mixing must feed also a tau neutrino component. Such UHE astrophysical tau
neutrino (noise-free from any atmospheric background) may interact in and it may
rises out the Earth as UHE τ. The UHE τ,¯τdecay in flight in atmosphere must lead
to loud Tau Air-showers. Such a detectable flashes may rise in short times within
Auger SD (by large electromagnetic curvature signals) or in FD arrays by horizontal
fluorescence signals, namely once in a few years (2 −4) from now 7),if the UHECR
are nucleons.
7. UHECR from Cen-A and the Lightest Nuclei spreads
Nevertheless a recent alternative UHECR understanding 3), based on observed
AUGER UHECR (nuclei) mass composition and with Cen-A rich clustering map, is
in disagreement with UHECR proton understanding 2). This UHECR understanding
is leading to different UHE neutrino predictions. It suggests that UHECR are made
by Lightest Nuclei (He2
4, He2
3, maybe also Li,Be), mostly originated from Cen-A.
The HE-like UHECR trajectories are bent and spread by spiral horizontal galactic
magnetic fields into vertical spread axis. Therefore UHECR appear as (incidentally)
clustered ( by galactic fields) around Cen-A just along the Super-Galactic Arm. Cen-
A is possibly an unique nearest source able to survive the short Lightest Nuclei
GZK cut-off. Virgo is too far (and a little out of view of AUGER detector). These
events spread mostly along the same Super-Galactic Arm apparently from far 80 Mpc
Figure 5: The Helium free length is more bounded than proton or iron nuclei. Its sharp decrease
may better fit the observed GZK knee. Its short distance may explain the Virgo (up to day) absence.
The UHECR arrival spread for any given energy will be proportional to the Z charge of Lightest
nuclei. For a given energy the UHECR spread in groups around Cen-A may offer a first spectroscopy
of lightest nuclei UHECR composition
See ref.?)
Centaurs Cluster. The mean random angle bending He2
4, Li3
6, Be4
8, by spiral galactic
magnetic fields along the plane are easily found δrm ≥:
11.3◦·Z
ZHe2
·(6·1019eV
ECR
)( B
3·µG)sL
20kpc slc
kpc (1)
16.95◦·Z
ZLi3
·(6·1019eV
ECR
)( B
3·µG)sL
20kpc slc
kpc (2)
22.6◦·Z
ZBe4
·(6·1019eV
ECR
)( B
3·µG)sL
20kpc slc
kpc (3)
This Lightest Nuclei for Highest Cosmic Rays model implies and foresees among
the other, additional clustering of UHECR events around the nearest AGN Cen-A
(the lightest UHECR the more correlated to the source, the heavier and with larger
charges, the most bent and spread ones). The model explains the absence or a poor
signal from Virgo (too far for the fragile nuclei to fly by) and possibly also from
Fornax. Such Lightest Nuclei for Highest Cosmic Rays are forced in a very confined
cosmic volume (ten Mpc or less) due to a fragile light nuclear (few MeVs) binding
energy. Usually heavy nuclei fragmentation pour energy only in UHE neutrino (at
0.1−0.01 EeV energy) spectra, less energetic than common UHE EeV p+γCMB →π
neutrino flux.
8. UHECR by Lightest Nuclei versus ντ
AUGER SD or FD are not able to reveal tens-hundreds PeV energy easily. How-
Figure 6: The first order bending for lightest UHECR, as He nuclei, is shown by the vertical arrow.
The underline galactic magnetic fields are spiral lines on Galactic Plane spreading, by Lorentz force,
vertically in Cen-A region, explaining the longitudinal clustering of the events, overlapping by chance
on Super Galactic Arm , shown by the dashed curve. It also explain the UHECR composition and
the possibly absence of Virgo. For a given energy (as the chosen threshold one) the UHECR spread
in groups around Cen-A may offer a first spectroscopy of few UHECR lightest nuclei
ever a very recent and a less spaced AUGER sub-system, a more dense array AMIGA
and the additional telescopes HEATS might lower the threshold accordingly. The
0.1EeV mostly hadronic, inclined-upward, tau air-showers θ≤80 occur at much
lower altitudes than hadronic inclined down-going air-showers, at much nearer dis-
tances from telescopes than hadronic EeV air-showers, reducing the area and the
rate. They may offer a tens-hundred PeV neutrino windows, secondaries of UHE He
nuclear fragmentation. Some estimates are offered assuming, for sake of simplicity a
Fermi-like UHE GZK spectra, comparable to the well known Waxmann-Bachall flux
derived for cosmic GRBs. Nevertheless if rarest UHECR, possibly from AGN, above
1−2·1020eV , ( a few in AUGER events), are also He nuclei, they may still suffer GZK
photo-pions opacity decaying into EeV neutrinos too. Such He GZK interaction may
be comparable with corresponding proton GZK ones at 6 ·1019eV : therefore EeV tau
Neutrino Astronomy, tails of the most energetic Lightest Nuclei GZK secondaries,
may still rise at AUGER. EeV inclined tau decays, born nearly at sea level (versus
inclined hadronic θ≥80 ones developing at altitudes well above ten km) occur at
air-density at least three times higher (than hadron horizontal ones); therefore Tau
Air-showers (mostly behaving as hadron ones), their electromagnetic and fluorescence
tail sizes (and times) are three times shorter (lsh ≈8−10 km) and their character-
istic azimuth speed ˙ϕ≈1.6·104rads−1is slower than common inclined UHECR
hadron ones at higher altitudes (lsh ≥25 −30 km), (25 −35 km), ˙ϕ≥5·104rads−1.
Such a brief 20 −30µs and distinct up-ward tau lightening versus slow 60 −90µs di-
luted down-ward horizontal showering may be well disentangled within AUGER (and
AMIGA SD) threshold, also by obvious angular resolution and directionality (up or
downward); their strong curvature and their inclinations would rise within HEAT
FD and AUGER FD, we estimate, once every a (2-3) years. Possibly (factor two)
originated from the Ande side (West to East )4),1),16).
Figure 7: The AUGER Array and the inner area AMIGA where lower energy air-showers might be
revealed by ground detectors. The two different spacing (5.9 km2and the 23.5 km2) offer a lower
energy threshold for neutrino inclined air-showers respectively at 1016 and 1017 eV . In the figure a
schematic area due to air-showering lobes of an escaping horizontal air-shower
Figure 8: As above the inner HEAT where lower energy air-showers might be revealed by Fluo-
rescence telescopes. In the figure a schematic array phototube where air-showering lobes of a near
and escaping Tau horizontal air-shower at few ten PeV energy. Tau will be raised at few km (2-3)
if at PeVs energy and at tens km (20-30) if of EeV nature. A more common downward-horizontal
hadronic airshower at tens EeV may split by geomagnetic fields shining at far distances and very high
altitudes (25-35) km. Almost ever outside the AUGER ground detector area. The altitude, timing,
angle spread are unique imprint. They may serve to disentangle Nuclei-versus nucleon UHECR
nature.
This new neutrino Astronomy, the PeVs-EeVs ratio, may disentangle in future
records the real UHECR nucleon or lightest nuclei UHECR nature. Indeed the addi-
tional rise of the resonant Glashow contribute, ¯νe+e→W−→¯ντ+τ, in the upgoing
Tau, while just marginally doubling the signal at 0.01 EeV. Leading to a flavor UHE
neutrino spectroscopy.
8.1. The resonant ¯νe+e→W−→¯ντ+τ
The role of UHE neutrino interaction with matter is well understood: they also
shape the neutrino survival across the Earth. Indeed the highest energy νare opaque
to Earth, but not to smallest cord. Therefore the harder events are the more tangent
ones. The resonant ¯νe+e→W−→¯
ντ+τare very peculiar signals. Their opacity
on Earth is extreme. They are as opaque as EeV energetic neutrinos. But their lower
energy corresponds to higher flux (for constant energy fluency as Waxmann Bachall
one). But their propagation in Earth is much smaller too. The compensated flux in
5-6 times higher than EeV one. Unfortunately this rate is (in AUGER) suppressed by
detection threshold (nearly one hundred times smaller than EeV showers). Neverthe-
less the mini array AMIGA (of 6 km2) and the HEAT telescopes may contribute to
make detecable in a few year the same resonant ¯νe+e→W−→¯
ντ+τ: the distance
will be ten times smaller and the showering azimuth angular velocity will appear ten
times faster than already fast EeV Tau Airshower. Their curvature in AMIGA may
leave a clear imprint.
9. Conclusions: UHE ντAstronomy by UHECR beyond the corner
UHECR Astronomy is a new windows achieved last few years. We believe that
UHECR signal rose with definitive direction mostly from Cen-A. We explained why
He-like lightest nuclei solve most composition puzzles and the smearing nature of
these CEN-A events. We foresee (as soon data by AUGER will be released): a)
additional UHECR clustering along Cen-A in the ”vertical” axis (as earlier events),
testing somehow the light nuclei composition. b) the possible emergence of a smeared
Virgo if and only if also heavier C−N−Onuclei are ejected; otherwise He-like are
the main currier; c) the possible more smeared presence of diffused isotropic events
as fragments of far sources (with little astronomical meaning).d) The Virgo might be
soon a hidden (by the Earth shadows) source of skimming UHE HE-GZK neutrinos, at
best beyond the Ande. Either by EeV GZK 14),17)secondaries if AUGER did reveal
nucleons or, following light nuclei model, by tens PeV signals. Their detection via
FD in AUGER and HEAT is, we believe, at the edge. The short and near air-shower
from the FD telescope (due to the lower energy thresholds) makes their Tau airshower
timing brief, sharp and at small zenith angle,as well as up-going. On the contrary the
rarest inclined horizontal down-going hadron shower are far away, diluted in air den-
sity and spread in much longer time scale. They are often bifurcate (by geomagnetic
field). No way to be confused. Three or more times duration and morphology of up
or down signature will disentangle any rare neutrino lights arriving from their unique
but unusual sky: the Earth. Their rate, timing, energy and inclination may teach us
Figure 9: The earliest prediction of AUGER group versus expected fluxes (ICRC-2005) by AUGER
group. Note a nominal 10-20 years duration for an event Tau versus our 3-4 years rate.
Figure 10: The recent prediction of AUGER group versus our earlier expected fluxes (ICRC-2007)
by AUGER group. Note a nominal 6 years duration for an event Tau
Figure 11: The latest prediction of AUGER group (2009), versus expected fluxes by our past and
present paper, based also on possible UHECR HE-GZK nature. Note a nominal 1 −4 years rate for
an event, if UHECR are nucleon, versus a three years at tens PeV, for a UHECR-He nuclei
on the real nature (nucleon or lightest nuclei) of UHECR. In this hope we suggest (a)
to implement the present AUGER array with additional array searching for shadows
of inclined hadronic from Ande in AUGER; (b) To add Mini-Cherenkov telescope ar-
rays facing Ande screen to reveal tau air-showers signals beyond the mountain chain
also via direct Cherenkov flashes.(c) Locating a new telescope array few km distance
to reduce the energy thresholds (d) Introducing novel trigger detection by fast hori-
zontal track time signature.(e) Locating SD nearest to FD in order to enlarge their
ability to discover the inclined events (blazing Cherenkov flashes) both in FD and
in Cherenkov lights as well as in muon tracks in nearby SD array elements. It must
be remind that the AMIGA muon versus SD Cherenkov signal may well signal the
electromagnetic versus muon nature of horizontal air-shower, offering an additional
tool to disentangle neutrino versus hadronic air-showers. We foresee in very near
years, possibly this and next one, the Tau Neutrino Astronomy birth and blow-up,
if accurate attention on trigger thresholds, and AMIGA-HEATS implementation will
be concluded soon. Neutrino Astronomy by Tau exploit a natural amplifier, the air
shower , as a telescope. Its direction and view is the deeper microscope in star or
black-hole secret interiors. Incidentally the birth of tau neutrino astronomy may be
at the same time the first definitive probe of neutrino flavor mixing and reappearance.
10. References
1) Aramo C. et all.Astropart.Phys. 23 (2005) 65-77
2) [Pierre Auger Collaboration],Science, vol.318, p.939-943 (arXiv:0711.2256)
3) Fargion D. Phys. Scr. 78 (2008) 045901, 1-4.
4) D. Fargion, et al.: ”Horizontal Tau air showers from mountains in deep valley.
Traces of UHECR neutrino tau” 26th ICRC,He 6.1.09,p.396-398.1999.(USA);
Fargion D., 2002, ApJ, 570, 909; Fargion D.et.all. 1999, 26th ICRC,
HE6.1.10,396-398; Fargion D., et all. 2004, ApJ, 613, 1285; Fargion D. et
al., Nuclear Physics B (Proc. Suppl.)2004; Fargion D., et all. Adv. in Space
Res.,37 (2006) 2132-2138;,136 ,119; D.Fargion, J.Phys.Soc.Jpn.Vol.77 (2008)
Suppl. B., p.1-15.
5) Fargion D. Prog. Part. Nucl. Phys 57,2006,384-393; Fargion D. et al.
Adv.Space Res. 37 (2006) 2132-2138;
6) Fargion D. NO-VE-2006;astro-ph/0604430
7) Fargion D. et al. arXiv:0708.3645v2; Nucl.Inst. Meth.A, 588;2008, 146-150.
8) Gorbunov D.,et all, 2002, ApJ, 577, L93
9) Bertou X.et.all 2002, Astropart. Phys., 17,183
10) Blanch B., Auger Coll.,ICRC07,arXiv:0706.1658v1
11) A.Watson interview, www.phys.psu.edu
12) Auger Collaboration, Phys. Rev. Letters 100 (2008) 211101
