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Volume 331 - Frontier Research in Astrophysics – III (FRAPWS2018) - Opening Remarks
No Tau? No Astronomy
D. Fargion,* P. Oliva,, P. Lucentini,, P. Paggi,, F. LaMonaca,, M. Khlopov
*corresponding author
Full text: Not available
Abstract
Since 2013, the highest energy IceCube cascade showers overcame the common muon neutrino tracks. This fast flavor changes, above few tens TeV, has been in debt to the injection of the longsearched astrophysical neutrino. However for what concern the recent published 54 neutrino High Energy Starting Events (HESE) in 2016, as well as the most recent ones of 82 and 103 IceCube
events (2017-2018) and the several dozens of thorough-going muon tracks formed around the IceCube, none of them are pointing or clustering toward any expected x, gamma or radio sources:
no one in connection to GRB, no toward active BL Lac, neither to AGN source in Fermi catalog. No clear correlation with nearby mass distribution (Local Group), nor with galactic plane. Withal,
there have not been any record of the expected double bang due to the tau neutrino birth and decay among several events above 200 TeV energy (we are disregarding for a moment the most recent
two tau possible identification); no any self-clustering events at tens TeV energy raised in most recent search. Furthermore, there is a tension between the internal HESE event spectra power
index and the external thorough-going muon tracks one.
As we will show at the conclusions a more mundane (but a bit more abundant) prompt charmed atmospheric neutrino component may pollute and rule the data, explaining most of the present
enlisted IceCube puzzles. We review the last HESE event data shown in early and in most recent papers (and talks in Neutrino 2018) making the case for the simplest conclusions. A very recent,
unique, celebrated thorough-going muon in IceCube on 22=09=2017 track possibly correlated to a gamma AGN (TXS 0506+056), and two revisited HESE events of possible tau neutrino
nature, are mitigating the IceCube tau absence, but as we show more abundant tau signals are needed to confirm an astrophysical nature. A better filtered and guaranteed neutrino astronomy
it is required: the tau flavor ones above TeVs have negligible or none (oscillated atmospheric) polluted background; very few percent of highest atmospheric charmed events may contribute to
the noise (possibly the two event observed by IceCube). Astrophysical tau are possibly arising at best at highest energies (PeVs ones) ultimately overcoming noises and their tracks at hundred PeV edges may overcome the same atmospheric muon tracks. Tau neutrino astronomy is therefore the
best road to highest energy neutrino astronomy. It may be revealed in double bangs in future IceCube events, by their tau birth first and their later decay in ice. A much sharp signal is made
by upgoing-horizontal tau air-showers originated within mountain chain or inside Earth crust and better observable from mountains, balloons or from space, by large size array detectors (PAO
observatory, Telescope Array, MAGIC telescope, Ashra, GRAND, POEMMA, ANITA). Some of these tau events might be already hidden in most recent ANITA up-going records at tens or
hundred PeV. In conclusion we claim that in IceCube events are probably still sunk in a very polluted conventional and mostly prompt neutrino noise. Their dominance it is probably due to
atmospheric charm emergence at a little higher rate than the expected one. We believe therefore that most astrophysical neutrino signals are still hidden below the ashes of these new, anyway discovered, prompt atmospheric noise.


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