Exploiting Hard Probes to Study the Quark Gluon Plasma

Hard probes — energetic partons and electroweak bosons born in the earliest instants of a heavy-ion collision — have become precision tomographs of the Quark Gluon Plasma (QGP). This talk will survey the rapid progress made possible by novel analyses with the upgraded LHC detectors and by the start-up of sPHENIX at RHIC, highlighting how unprecedented kinematic reach and angular resolution now bridge experimental observables to quantitative QCD theory.

After a concise review of the conceptual foundations of jet quenching, heavy-flavor energy loss, and boson–jet correlations, I will present new measurements that isolate path-length and color-charge dependencies of partonic energy loss across a broad range of system sizes and collision energies. Emphasis will be placed on the studies of full-jet and its substructure; charm- and beauty-tagged observables, including high-precision charm and beauty hadron spectra that constrain heavy-quark diffusion; and Z/γ-hadron and Z/jet correlations that serve as calibrated probes of medium response. Finally, an outlook will be presented.