Non-equilibrium Dynamics of the Quark Gluon Plasma

Michael Strickland, Kent State University (principal investigator)

Understanding the non-equilibrium dynamics of the quark-gluon plasma (QGP) is important for interpreting the data produced in ultrarelativistic collisions 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 two heavy nuclei collide at nearly the speed of light.  In the wake of such collisions, a short-lived (lifetime < 10^-22 s) state 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 lifetime.  Understanding how a far-from-equilibrium QGP can approach local thermal equilibrium on such short time scales requires investigations using quantum chromodynamics and dissipative relativistic hydrodynamics.  In this work, the PI extends the recently developed framework of anisotropic hydrodynamics and applications thereof.  This will help to provide a better picture of the non-equilibrium dynamics occurring in both 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.