Ultrahigh energy neutrino scattering: an update

TL;DR

This paper updates predictions of ultrahigh energy neutrino cross sections using a Froissart-bounded fit to recent HERA data, showing smaller cross sections than traditional pQCD extrapolations at energies above 10^9 GeV.

Contribution

It introduces a new fit based on the Froissart bound and recent HERA data to improve ultrahigh energy neutrino cross section estimates, contrasting with previous pQCD-based models.

Findings

Predicted neutrino cross sections are significantly smaller than pQCD extrapolations.

Updated fit uses recent ZEUS and H1 data for more accurate estimates.

Results support previous conclusions about cross section sizes at ultra-high energies.

Abstract

We update our estimates of charged and neutral current neutrino total cross sections on isoscalar nucleons at ultrahigh energies using a global (x, Q^2) fit, motivated by the Froissart bound, to the F_2 (electron-proton) structure function utilizing the most recent analysis of the complete ZEUS and H1 data sets from HERA I. Using the large Q^2, small Bjorken-x limits of the "wee" parton model, we connect the ultrahigh energy neutrino cross sections directly to the large Q^2, small-x extrapolation of our new fit, which we assume saturates the Froissart bound. We compare both to our previous work, which utilized only the smaller ZEUS data set, as well as to recent results of a calculation using the ZEUS-S based global perturbative QCD parton distributions using the combined HERA I results as input. Our new results substantiate our previous conclusions, again predicting significantly smaller cross sections than those predicted by extrapolating pQCD calculations to neutrino energies above 10^9 GeV.