Physics professor receives DOE grant to study the quark-gluon plasma
Up until approximately 10^(-5) seconds after the Big Bang, the Universe was in a primordial state of matter called a quark-gluon plasma (QGP). This is due to the fact that the early Universe was extremely hot and, in such a hot environment, normal matter, e.g., atoms, atomic nuclei, and even neutrons and protons, did not exist. Fundamentally, the melting of protons of neutrons in the early Universe is predicted to occur at temperatures on the order of 2 trillion Kelvin, with this temperature being predicted by the fundamental theory governing quarks and gluons, which is called Quantum Chromodynamics (QCD). QCD is one component of the standard model of particle physics, which describes the strong force. These days it is possible to produce such temperatures using relativistic heavy-ion collisions, e.g. colliding gold nuclei on gold nuclei at 99.9999% the speed of light. Understanding the non-equilibrium dynamics of the QGP is important for interpreting the data produced in relativistic collisions being performed at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory and the Large Hadron Collider at CERN.
In such collisions a small droplet of QGP is created when the two heavy nuclei collide. In the wake of such collisions, a short-lived state (lifetime < 10^(-22) s) with energy density well exceeding 1 GeV/fm3 is created, which maps to temperatures on the order of 4-7 trillion Kelvin. Such temperatures are sufficient to deconfine the quarks and gluons into the primordial soup called the QGP. Surprisingly, experimental indications are that the QGP exhibits properties of a near-equilibrium thermal system at the end of its very short lifetime. Understanding how a far-from-equilibrium QGP can approach local thermal equilibrium on such short time scales requires investigations using QCD and dissipative relativistic hydrodynamics. Dr. Strickland received a continuation of his grant from the Department of Energy (DOE) to further extend the framework of anisotropic hydrodynamics, which was developed by himself and collaborators. This work will help to provide a better picture of the non-equilibrium dynamics occurring in heavy-ion collisions (AA) and collisions involving "small systems", e.g. proton-nucleus (pA) and proton-proton (pp) collisions. The work on anisotropic hydrodynamics is also coupled with complementary work on effective kinetic theory applied to QCD and bottomonium suppression in an open quantum system. This most recent funding continues the support of Dr. Strickland by the DOE, which began in 2015 and has to amounted thus far to over $1.55 million as a single PI award. This funding supports theoretical particle physics research into QGP physics through the training of graduate students and postdoctoral associates at Kent State University.