Ultra-relativistic collisions of heavy ions at the Relativistic Heavy Ion Collider (RHIC) and at the Large Hadron Collider (LHC) create an extremely hot system at temperatures (T) expected within only the first microseconds after the Big Bang. At these temperatures (T ~ 2 x 1012K), which are several hundred thousand times hotter than the sun's core, normal hadrons cannot exist and nuclear matter "melts" to form a "soup" of quarks and gluons. At RHIC, the soup flows with extremely low viscosity, suggesting a nearly perfect hot liquid of quarks and gluons. Furthermore, the liquid is opaque to very energetic quark and gluon probes (partons) providing evidence that it is dense and highly interacting. I will present a motivation for physics in the field, overview and interpret the RHIC results, highlight the first results from heavy ions at the LHC and discuss them in relation to the RHIC results.
Argonne Physics Division Colloquium Schedule