Neutrino Astronomy (Rapporteur Talk)

Abstract

This report is the write-up of a rapporteur talk on neutrino astronomy given at the 34th International Cosmic Ray Conference in The Hague, Netherlands, in 2015. Here, selected contributions on the neutrino astronomy from the total of 40 talks and 90 posters presented in NU sessions at the 34th ICRC are summarized in the attempt of providing a status report on this rapidly glowing new field. The field of neutrino astronomy has recently experienced a "phase transition" since the first observation of high energy cosmic neutrinos. Extensive efforts have been made to identify the origin of the neutrino flux observed in the 100 TeV to PeV region, from both theoretical and experimental perspectives. In addition, the search for neutrino fluxes beyond the observed level has become increasingly important for further understanding the origin of the observed cosmic-ray up to 10 20 eV. Although the IceCube Neutrino Observatory is the only experiment currently measuring this neutrino flux, its initial measurements have been confirmed via analysis using several independent detection channels. Further, there have been a number of developments in the search for neutrino point sources, while no successful observations have yet been reported. Following the IceCube observations, a large number of studies of next-generation neutrino detectors, including up-scaled underground Cherenkov neutrino detectors and Cherenkov radio neutrino detectors, have been reported.

No guaranteed neutrino astronomy without (enough) double bang tau and downward HESE muon tracks: An update version

“…The article is structured as follows: in the present introduction (1) we are considering in 1.1 the double bang and tau airshower: the imprint of any neutrino Astronomy; therefore, in 1.2, the open question in ICECUBE data. In present subsection, we are offering the article structure view, 1.3.…”

“…Let us recall the old (2015-2016, [1,2]), recent (2017 [3,4]) and last (2018, [5,6]) ICECUBE data set with 54, 82 and 103 events reported in the figure 1, 4 and 5. We can notice how two events, marked with the label 3 and 4 in the figures 1, 4, have been moved between the first two dataset issues to a lower energy, below the 200 TeVs threshold, being de facto excluded from the hard detectable group.…”

“…But not for prompt atmospheric neutrinos that has no time and distances to oscillate and mix. The consequence is the follow: if ICECUBE neutrinos are all astrophysical as the highest ones at 200 TeV and above should be, than the expectance of the tau presence or absence is given by simple binomial distribution: in particular assuming an astrophysical neutrino where there is an equal probability to observe an electron, a tau or a muon or their Neutral Current at equal 1 4 rate,…”

“…ICECUBE published over the years sets of contained neutrino events, with the name of High Energy Starting Events, or HESE. We refer in particular to a first set with 54 events in 2015-2016 [1,2], then a following one with 82 events in 2017 [3,4] and the last with 113 events, later reduced to 103, in 2018 [5,6]. Indeed, none of them is pointing or clustering toward any of the several expected transient candidate X ray, gamma or radio sources with the exceptions of the recent and unique ICECUBE-170922A alert correlated within weeks and months to the active AGN source.…”