  Jets are important probes of heavy ion collisions as they can provide
information on the interaction of a highly energetic parton with the medium it
traverses. In the hydrodynamic stage of dense, strongly interacting matter,
these interactions can be explained in terms of scattering processes, soft
gluon emission and collinear parton splittings. However, jets originate even
before the hydrodynamic stage. Here we report on the first numerical simulation
of transverse momentum broadening of jets stemming from the interaction of
partons with boost-invariantly expanding Glasma flux tubes. The Glasma stage is
a pre-hydrodynamic stage based on the Color Glass Condensate framework. Our
calculation shows strong time-dependence and an intrinsic anisotropy of
momentum broadening in the directions transverse to the jet propagation
direction.
