  Analysis of semi-inclusive DIS hadroproduction suggests broadening of
transverse momentum distributions at $x$ below a few $10^{-3}$, which can be
modeled in the Collins-Soper-Sterman formalism by a modification of
impact-parameter-dependent parton densities. We discuss the consequences of
such a modification for the production of electroweak bosons at hadron-hadron
colliders. If substantial small-$x$ broadening is observed in forward Z boson
production in the Tevatron Run-2, it will strongly affect predicted transverse
momentum distributions for W, Z, and Higgs boson production at the Large Hadron
Collider.

High Energy Physics - Phenomenology