Dynamical QCD predictions for ultrahigh energy neutrino cross sections

Abstract

Neutrino-nucleon total cross sections for neutrino energies up to ultrahigh energies (UHE), E ν = 10 12, GeV, are evaluated within the framework of the dynamical (radiative) parton model. The expected uncertainties of these predictions do not exceed the level of about 20% at the highest energies where contributions of parton distributions in the yet unmeasured region around x ⋍ 10 −8, to 10 −9 are non-negligible. This is far more accurate than estimated uncertainties of about 2 ±1 due to fixed power law extrapolations of parton distributions to x < 10 −5 required for calculating UHE cosmic neutrino event rates.