Influence of Cosmic-Ray Spectrum and Hadron-Nucleus Interaction Model on the Properties of High-Energy Atmospheric-Neutrino Fluxes

摘要

The neutrino/antineutrino flux ratios (nu(e)/(nu) over bar (e) and nu(mu)/(nu) over bar (mu)) and the flavor ratio (nu(mu)/(nu) over bar (mu))/(nu(e)/(nu) over bar (e)) clearly demonstrate the distinctions between the predictions of hadronic-interaction models for the production spectra of pions and kaons, which are the main sources of atmospheric neutrinos in the region of E-nu less than or similar to 500 TeV. The values of the nu/(nu) over bar ratio are sensitive to variations in the pi(+)/pi(-), pi/K, and K+/K- meson ratios, which are determined by the cross sections for inclusive meson-production processes in hadron-nucleus (hA) collisions; the elemental composition of cosmic rays also exerts influence, through the p/n ratio, on the development of hadronic cascades and on the neutrino ratios. The difference in nu/(nu) over bar. and in the flavor ratio for a number of hadronic-interaction models is shown on the basis of calculating neutrino fluxes at energies in the range between 10(2) and 10(8) GeV. A comparison of the calculated results with new experimental data shows the reliability of this calculation, which, on the whole, reflects correctly the mechanism of atmospheric-neutrino production. The spectra of atmospheric muon neutrinos from calculations based on the Kimel-Mokhov, SIBYLL 2.1, and EPOS LHC models describe fairly well experimental results. At energies in the range of 1- 500 TeV, the curves calculated within these models combined with the Hillas-Gaisser spectrum are close to the best fit to data from measurements in the IceCube experiment.