Calibrated Probes of Jet-Medium Interactions in Hot and Cold Nuclear Matter

Ultrarelativistic collisions of large nuclei are understood to produce droplets of quark-gluon plasma (QGP), a deconfined phase of QCD matter that exists at high temperatures $\gtrsim 155$ MeV. {\em Jet quenching} is one of the key signatures of this phase, and is attributed to energy loss via collisional and radiative interactions between high-energy, strongly interacting probes and the plasma. Quenching model predict the lost energy to reemerge at low momentum scales, however data in this regime is limited by the background of low-momentum hadrons produced by the expanding and cooling medium. At the LHC, $Z^0$+jet scattering events offer new insights to a more complete picture of the quenching phenomenon. Simultaneously, collisions of smaller nuclei consistently exhibit momentum anisotropies and other signatures traditionally associated with a QGP phase. Within current uncertainties, jet-quenching scenarios have neither been detected nor ruled out, particularly in central $p$+Pb collisions. To fully map out the minimal formation conditions for QGP droplets, a deeper understanding of small system dynamics is required. This dissertation presents two new measurements of jet quenching in Pb+Pb and $p$+Pb collisions utilizing calibrated probes to tag hard-scattering events. The first is a measurement of $Z^0$-tagged charged hadron yields in Pb+Pb collisions. The color-neutral $Z^0$ boson tags the initial hard scattering, and a significant depletion of high-momentum hadrons is strongly sensitive to parton energy loss. At the very lowest momenta, a modest enhancement of hadrons is also observed, suggesting a redistribution of energy to the medium. Comparisons to theoretical expectations help build a more complete picture of the jet-medium interaction. The second study builds this analysis technology further by measuring jet-tagged hadron yields in central $p$+Pb collisions. The hadron yield in this system is found to be unmodified across a broad kinematic range to within a few percent, providing strong further constraints on potential energy loss phenomena in small systems.