QCD Jets in QCD Matter
Thirty years ago, Bjorken proposed utilization of QCD jets as a tomographic probe of Quark-Gluon Plasma that may be generated in high energy hadronic collisions ("jet quenching"). Initial measurements of jet quenching at RHIC were indirect, based on suppression of high momentum hadrons and their correlations. More recently, first attempts at direct measurement of jet quenching via reconstruction of the complete hadronic shower of a jet in heavy ion collisions have been reported at the LHC. Heavy ion jet measurements are especially challenging, however, due to the large and complex event background, and currently reported results may have hidden biases and instrument-specific effects. I will present an alternative approach that enables the measurement over a wide kinematic range of manifestly infrared and collinear-safe (IRC) jet distributions, in the complex environment of heavy ion collisions. I will show applications of this approach to current data from the ALICE experiment at the LHC and the STAR experiment at RHIC, and discuss the consequences for our understanding of jet quenching.