Screening effects in the ultra-high energy neutrino interactions

We study possible saturation effects in the total crosssections describing the interaction of ultra-high energy neutrinos with nucleons. This analysis is performed within two approaches, i.e., within the Golec-Biernat-Wüsthoff saturation model and within the scheme unifying the DGLAP and BFKL dynamics incorporating non-linear screening effects which follow from the Balitzki-Kovchegov equation. The structure functions in both approaches are constrained by HERA data. It is found that screening effects affect the extrapolation of the neutrino-nucleon total cross-sections to ultra-high neutrino energies and reduce their magnitude by a factor equal to about 2 at GeV. This reduction becomes amplified by nuclear shadowing in the case of the neutrino-nucleus cross-sections and an approximate estimate of this effect is performed.Received: 26 March 2003, Revised: 17 April 2003, Published online: 3 July 2003