Abstract:
Quantum Chromodynamics (QCD) is a complete theory of the strong interaction. However, generally calculations with QCD are notoriously difficult. In particular, the phases of quark matter are poorly understood. Predicted by lattice QCD calculations, the Quark-Gluon Plasma can be created in relativistic heavy ion collisions. This strongly interacting quantum liquid, first discovered at the Relativistic Heavy Ion Collider (RHIC), was found to flow more freely than any other known fluid with charged particle angular correlation analyses.
To go beyond the studies of the debris of the QGP, we can study the passage of color charged particles through this fascinating medium. One studies heavy ion collisions which produce not only the QGP but also heavy quarks, energetic gluons and quarks by chance. High energy quarks and gluons lose energy by radiating gluons or by colliding with the other quarks and gluons as they traverse through the QGP, a phenomenon often referred to as “Jet Quenching”. The slow-moving heavy quarks, which are interacting with the QGP strongly, open a window to the study of in-medium color force.
In this talk, I will review the most striking observations made in recent data collected by the Compact Muon Solenoid detector at the Large Hadron Collider and the properties of the QGP fluid extracted from these measurements.
Brief Bio:
Yen‐Jie Lee completed his undergraduate degree and Master’s in Physics at the National Taiwan University under the supervision of Prof. Min-Zu Wang and his doctoral work at MIT in 2011 under the supervision of Prof. Wit Busza. After postdoctoral work at the Laboratory for Nuclear Science at MIT, he completed a combined CERN and Marie Curie Fellowship at CERN from 2012 to 2013. He joined the MIT Physics faculty in September 2013 and was promoted to Associate Professor of Physics in 2018.
Prof. Lee’s research aims to move beyond discovery‐era qualitative measurements of QGP and to understand QCD matter in extreme conditions, such as those that existed in the first microseconds of the universe and that are thought to exist at the core of some neutron stars. He served as one of the Heavy Ion Physics Group co-conveners in the CMS collaboration from 2014 to 2016. He also served as heavy-ion physics executive board representative in the CMS collaboration between 2016 and 2018.
Prof. Lee received an Early Career Research Award from the U.S. Department of Energy in 2015, an NEC Corporation Fund Award from the MIT Research Support Committee, a Sloan Research Fellowship from the Alfred P. Sloan Foundation in 2016 and a Class of 1958 Career Development Professorship since 2016.