Title: Quark-Gluon Plasma: An Old and New Phase of Quantum Matter
Abstract: The use of fire was instrumental for human civilization. Early conception of varied phases of matter as well as transitions among them, perhaps developed from e.g. burning wood and heating water. Those ancient pursuits continue into the modern quest for understanding the structure of matter under extreme conditions: what’s the phase of matter when heated to unprecedented temperature? The answer to this question relies upon our understanding of the strong nuclear force, which is described by quantum chromodynamics (QCD). First principle calculations of QCD predict that the normal nuclear matter, when heated to be hot enough, will change into a new phase of matter called the quark-gluon plasma (QGP). In fact, the QGP was an old phase of matter that occupied the early universe shortly after the Big Bang. Today, such primordial droplets of QGP can be re-created repeatedly and measured precisely in relativistic heavy ion collisions (often called the Little Bangs). Remarkable discoveries have been made at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) that together reveal the QGP as a nearly perfect quantum liquid with superior opaqueness. We will discuss a number of novel properties of QGP. In particular we will highlight the recent progress on how certain unusual transport phenomena stemming from microscopic chiral anomaly, which is intrinsically quantum mechanical, could manifest themselves in the macroscopic QGP fluid. A brief survey will be given on the theoretical developments, the experimental search in heavy ion collisions, as well as the recent exciting progress of such physics in Dirac and Weyl semimetals.
Colloq flyer 2-3 Liao