The 9th International Conference on Hard and Electromagnetic Probes of High-Energy Heavy-Ion Collisions (Hard Probes 2018) was hosted in Aix-Les-Bains (Savoie, France) from October 1st-5th, 2018, with a student lecture day hosted at CERN on September 30th. Hard Probes focuses on experimental and theoretical developments on perturbative probes of hot and dense QCD matter as studied in high-energy nucleus-nucleus, proton-nucleus and proton-proton collisions. The 6-member delegation from the MIT Heavy Ion Group presented several high-impact results, distributed over many areas of interest.
The group’s contributions to the conference began with Professor Yen-Jie Lee’s plenary talk showcasing the “Highlights on Hard Probes from CMS” on the morning of October 1st. This was followed by several parallel talks on October 2nd: early that morning, Austin Baty presented the results of measurements of “Charged Particle Nuclear Modification Factors in pPb, PbPb, and XeXe Collisions with CMS;” the comparison of XeXe and PbPb collisions was used to constrain the path-length dependence of various energy loss models. In the afternoon, Michael Peters presented the results of the first measurement of “D-meson production in jets in pp and PbPb collisions with the CMS detector,” providing insights into the dynamics of charm-quark propagation in heavy-ion collisions. Afterward, Kaya Tatar presented measurements of “Photon-tagged jet fragmentation functions and jet shapes in pp and PbPb collisions with the CMS detector,” in which the final version of the jet shape measurement was presented for the first time; by measuring jets associated with isolated photons, these measurements constrain the initial parton kinematics and energy loss of quark jets in-medium.
The next day, October 3rd, Yi Chen presented “A step towards tagging of quenched jets“, which detailed the efforts in the implementation of techniques to attempt to study the initial hard splitting in jet fragmentation. The group’s contributions were closed with Professor Gunther Roland’s plenary talk “Everything you always wanted to know about sPHENIX at RHIC,” which summarized developments in the sPHENIX detector commissioning. Prof. Roland also participated in a panel discussion regarding the future of the field of experimental heavy ion physics.