Speakers
Description
Talk 1 (20 min): Prof. Zhenyu Chen (Shandong University)
Title:
How Far That Little Candle Throws His Beams! -- Collectivity in Small Systems: Experimental Insights and Open Questions
Abstract:
Small collision systems exhibit signatures of collectivity similar to those observed in heavy-ion collisions, yet their dynamical origin remains an open question. Drawing on the similarities and differences between small and large systems, this topical talk discusses selected open questions in collectivity from an experimental perspective and their implications for understanding the underlying dynamics.
Brief introduction about the speaker:
Zhenyu Chen is a professor at Shandong University. He obtained his Ph.D. from Rice University in 2017 and subsequently worked as a postdoctoral researcher at Rice University and Stony Brook University before joining Shandong University in 2019. His research focuses on collectivity and polarization in heavy-ion collisions, with a recent focus on small systems.
Talk 2 (25 min): Dr. Shujun Zhao (Sophia University)
Title:
Exploring the existence of QGP droplet in p-p collisions at LHC
Abstract:
The observation of collectivity in small collision systems challenges conventional expectations for QGP formation. It also raises questions about the applicability of hydrodynamics in these systems. In particular, a key difficulty is to consistently describe the far-from-equilibrium early-stage dynamics, where large pressure anisotropies can influence the subsequent evolution and final-state observables. In this talk, we introduce viscous anisotropic hydrodynamics (VAH), which treats pressure anisotropy non-perturbatively and provides a framework for describing the evolution from an anisotropic, far-from-equilibrium state towards the near-equilibrium hydrodynamic regime in a consistent way. We then apply VAH to high-multiplicity p-p collisions. The framework describes the measured two-particle flow coefficients v2{2} and v3{2} over a broad multiplicity range and reproduces the negative sign of the four-particle flow cumulant c2{4} observed experimentally. These results support the possibility of QGP formation in p-p collisions.
Brief introduction about the speaker:
Shujun Zhao is a postdoc at the Department of Physics, Sophia University. He received his B.S. (2020) from Jilin University and Ph.D. (2025) from Peking University. His research interests include the transport properties of the quark-gluon plasma (QGP), the interplay of nuclear structure with high- and intermediate-energy nuclear physics, and small-x physics.
