  The last few years have seen community-wide excitement in the study of jet
substructure derived from the inner workings of clustering algorithms. Such
efforts have resulted in the design of new observables which are related to
partonic processes from final state hadrons. Since jets are multi-scale
objects, they necessarily encode information about both the perturbative (pQCD)
parton shower and non-perturbative (npQCD) physics including hadronization.
Recent high precision measurements of jet substructure in proton-proton (pp)
collisions have pushed the theoretical community into extending their
predictions to higher orders resulting in the observation of large theoretical
uncertainties from the non-perturbative regime of the calculations. We
emphasize the importance of understanding a jet shower from a multi-dimensional
point of view and highlight a recent measurement focused on distinguishing the
pQCD vs. npQCD regimes within a jet shower. We introduce and discuss the
utility of the formation time evaluated at varying stages of the jet shower in
pp collisions. Finally, we present a monte-carlo study of the formation time of
charged particles within the jet to gain a handle on hadronization mechanisms
including string-breaking, and outline a path forward for such observables in
heavy ion collisions.
