  Back-to-back light and heavy flavor dijet measurements are promising
experimental channels to accurately study the physics of jet production and
propagation in a dense QCD medium. They can provide new insights into the path
length, color charge, and mass dependence of quark and gluon energy loss in the
quark-gluon plasma produced in reactions of ultra-relativistic nuclei. To this
end, we perform a comprehensive study of both light and heavy flavor dijet
production in heavy ion collisions. We propose the modification of dijet
invariant mass distributions in such reactions as a novel observable that shows
enhanced sensitivity to the QGP transport properties and heavy quark mass
effects on in-medium parton showers. This is achieved through the addition of
the jet quenching effects on the individual jets as opposed to their
subtraction. The latter drives the subtle effects on more conventional
observables, such as the dijet momentum imbalance shifts, which we also
calculate here. Results are presented in Pb+Pb collisions at $\sqrt{s_{NN}}$ =
5.02 TeV for comparison to data at the Large Hadron Collider and in Au+Au
collisions at $\sqrt{s_{NN}}$ = 200 GeV to guide the future sPHENIX program at
the Relativistic Heavy Ion Collider.
