  We investigate the effect of PT-broadening on jet substructure observables in
heavy-ion collisions at the LHC. As an example, we focus on the opening angle
of the two branches that satisfy the soft drop grooming condition in a highly
energetic jet. The medium modification of the angular distribution can provide
important information on the jet transport properties of hot QCD matter. In
addition, we take into account a change of the overall fraction of quark and
gluon jets in heavy-ion collisions. We comment on the comparison to a recent
measurement from the ALICE Collaboration.
