  We introduce a systematic approach for the resummation of perturbative series
which involve large logarithms not only due to large invariant mass ratios but
large rapidities as well. Series of this form can appear in a variety of gauge
theory observables. The formalism is utilized to calculate the jet broadening
event shape in a systematic fashion to next to leading logarithmic order. An
operator definition of the factorized cross section as well as a closed form of
the next-to leading log cross section are presented. The result agrees with the
data to within errors.
