UHE neutrinos: higher twists, scales, saturation

It is shown that in the ultra-high energy neutrino interactions the higher twist corrections brought about by the non-conservation of the top-bottom current dramatically change the longitudinal structure function, $F_L$. To the Double Leading Log Approximation simple and numerically accurate formulas for $F_L$ and $\sigma^{\nu N}$ are derived.Comment: 5 pages, 1 figure, Talk given at Diffraction 2010, Otranto (Lecce), Italy, September 10-15, 201