335 research outputs found
High-energy atmospheric neutrinos
High-energy neutrinos, arising from decays of mesons that were produced
through the cosmic rays collisions with air nuclei, form unavoidable background
noise in the astrophysical neutrino detection problem. The atmospheric neutrino
flux above 1 PeV should be supposedly dominated by the contribution of charmed
particle decays. These (prompt) neutrinos originated from decays of massive and
shortlived particles, , , , , ,
form the most uncertain fraction of the high-energy atmospheric neutrino flux
because of poor explored processes of the charm production. Besides, an
ambiguity in high-energy behavior of pion and especially kaon production cross
sections for nucleon-nucleus collisions may affect essentially the calculated
neutrino flux. There is the energy region where above flux uncertainties
superimpose. A new calculation presented here reveals sizable differences, up
to the factor of 1.8 above 1 TeV, in muon neutrino flux predictions obtained
with usage of known hadronic models, SIBYLL 2.1 and QGSJET-II. The atmospheric
neutrino flux in the energy range GeV was computed within the 1D
approach to solve nuclear cascade equations in the atmosphere, which takes into
account non-scaling behavior of the inclusive cross-sections for the particle
production, the rise of total inelastic hadron-nucleus cross-sections and
nonpower-law character of the primary cosmic ray spectrum. This approach was
recently tested in the atmospheric muon flux calculations [1]. The results of
the neutrino flux calculations are compared with the Frejus, AMANDA-II and
IceCube measurement data.Comment: Poster presented at XVI International Symposium on Very High Energy
Cosmic Ray Interactions (ISVHECRI 2010), Batavia, IL, USA (28 June - 2 July
2010); 4 pages, 4 figure
Retrieving the ratios of soft to hard velocity-changing collision's frequencies from H2O line profiles near 0.8 ΞΌm
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