Electroweak Double-logs at Small X

We investigate enhanced EW corrections to inclusive hard processes in the TeV energy region with emphasis on the small-x situation, in which the hard scale Q is significantly smaller than the available energy √ s ≡ Q/x. We first propose and justify a general factorization formula in which the (double-log) EW form factor at scale Q is factorized from EW parton distribution functions, which satisfy evolution equations of DGLAP type. We then investigate the small-x behavior of the EW parton distributions including the novel ones for non-vanishing t-channel weak isospin T and we compare it with a BFKL-type approach. In either approach we find that large small-x corrections of order αw log x logQ /M (M being the EW symmetry breaking scale) are present only for T=2 and not for T=1. This implies that only transverse WW interactions (coupled to T=2) are affected, while the T=1 components feel just the form factor at scale Q.