2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/194680IceCube, a cubic kilometer neutrino telescope will be capable of probing neutrino-nucleon interactions in the ultrahigh energy regime, far beyond the energies reached by colliders. In this article we introduce a new observable that combines several advantages: it only makes use of the upward-going neutrino flux, so that the Earth filters the atmospheric muons, and it is only weakly dependent on the initial astrophysical flux uncertainties.13 pages, Latex, 5 figures, added references, added contentHigh Energy Physics - Phenomenologytext