Kaon Decay Form Factors and Atmospheric Neutrino Flavor Ratio at High Energies

The dependence of the semileptonic kaon decay form factors on the 4-momentum transfer to the lepton pair causes certain changes in the differential decay rates and, hence, it should affect the conventional atmospheric neutrino flux and neutrino flavour ratio. As a case in point, we included these rates into the calculation of the atmospheric neutrino flux at energies 1 to 100 TeV. The calculated neutrino spectra are between the earlier predictions while the neutrino flavor ratio, R, is somewhat affected by the kaon form factors. The R proves to be very sensitive to the contribution of neutrinos from decay of charmed particles, providing an additional method to test the charm production models in future experiments with large-volume neutrino telescopes.