Data taken at the Relativistic Heavy Ion Collider (RHIC) since the year 2000 have shown conclusively that the high temperature phase of QCD matter is a quark- gluon plasma with the characteristics of a "nearly perfect" liquid. This finding has been confirmed by measurements in Pb+Pb collisions at much higher energy at the CERN Large Hadron Collider (LHC). The RHIC and LHC experiments have not only shown that the quark-gluon plasma behaves as a nearly inviscid liquid, but also that it is highly opaque to energetic partons, resulting in strong jet quenching. The physics goal for the next decade is to characterize the properties of this quark-gluon plasma liquid by quantitative extraction of important medium parameters from precision measurements of sensitive observables. The proposed INT program focused on the utilization of jets and heavy-quarks, since these are the two areas with the largest amount of progress in the past 5 years in terms of experimental capabilities, data taken and theoretical tools developed. Both, jets and heavy quarks, are hard probes that are being produced early on in the time-evolution of heavy-ion collisions in processes that are well described using perturbative QCD. They interact strongly with the surrounding QGP medium, and their measurable final state distributions yield significant information on the properties of the QGP medium, including its transport coefficients.

Highlights of the program included:

• An in-depth discussion on the current state-of- the-art regarding the calculation of the heavy flavor transport coefficient as well as its phenomenological extraction from data through a Bayesian analysis
• A workshop that brought leading jet energy-loss theorists and experimentalists together to discuss new jet energy-loss observables and how these map onto recent progress on the theory side
• A focus week on recent advances in jet energy-loss theory, including the calculation of transport coefficients at higher order in perturbation theory and the discussion of new sources of soft radiation at large angles
• A focus week on the creation and implementation of a community-wide jet energy-loss framework that would allow for the rigorous model-to- data comparison (via a Bayesian analysis) of most current major microscopic jet energy-loss models
• A discussion of the current status of quarkonium production and dissociation and how to advance this particular research area