  We study the event multiplicity dependence of the jet structure in pp
collisions. We present evidence for jet shape modification due to multi-parton
interactions using PYTHIA and HIJING++ Monte Carlo (MC) event generators as an
input to our analysis. We introduce a characteristic jet size measure which is
independent of the choice of the simulation parameters, parton distribution
functions, jet reconstruction algorithms and even of the presence or absence of
multi-parton interactions. We also investigate heavy-flavor jets and show the
sensitivity of the multiplicity-differential jet structure to flavor-dependent
fragmentation.
