Speaker
Description
Title:
Hard Probes in the Precision Era of Heavy Ion Physics
Joint IOPP Colloquium and HENPIC (The 256th HENPIC Seminar)
Time: September 22, 2026 (Tuesday), 10:30-12:00 (Beijing time, UTC+8)
Zoom meeting ID: 98708774920
Abstract:
Over the last decades, experiments at RHIC and at the LHC have established a consistent picture of the quark-gluon plasma as a close-to-perfect fluid with minimal dissipative properties, in which collective behavior develops on remarkably short timescales. Signatures of QGP collectivity had long been observed in ultra-relativistic heavy-ion collisions, but essentially all of these signatures have also been identified over the last decade in collision systems as small as pp and p-Pb, where collective phenomena had traditionally been assumed to be absent. This has opened up a new set of questions about the emergence of QGP collectivity and about the microscopic properties of the matter created in these collisions.
The first part of this seminar will review the main elements of our theoretical understanding of ultra-relativistic heavy-ion physics, with a focus on those open questions that will come within experimental reach in the heavy-ion programme at the HL-LHC. In this precision era, the improved experimental capabilities will allow us to confront theoretical descriptions of the QGP with increasingly differential and quantitative measurements.
As specific examples, I will focus in particular on hard probes, including heavy-flavor transport and jet quenching. These observables provide complementary ways of probing the microscopic dynamics of the QGP, but their interpretation at the precision level will require not only improved phenomenological modeling but also conceptual advances in our theoretical description of how hard probes interact with an evolving QCD medium.
Brief introduction about the speaker:
Urs Achim Wiedemann is a senior physicist in CERN's Department of Theoretical Physics, where he currently serves as department head. His research has long focused on the theory and phenomenology of strong interactions under the extreme temperature and density conditions created in ultra-relativistic heavy ion collisions.
