In this work, we obtain the leading corrections to the jet momentum
broadening distribution in a QCD medium arising from the transverse flow of the
matter. We first derive the single-particle propagator of a highly energetic
parton resumming its multiple interactions with the homogeneous flowing matter,
explicitly keeping the leading subeikonal flow terms. Then, we use this
propagator to obtain the jet broadening distribution and its leading moments.
We show that this distribution becomes anisotropic in the presence of
transverse flow, since its odd moments are generally non-zero and proportional
to the transverse velocity of the medium. Finally, we evaluate several odd
moments, which we compare to the corresponding results at first order in
opacity, showing that accounting for multiple in-medium scatterings is
essential to describe some observables in dense nuclear matter.Comment: 28 pages, 2 figure