The colour glass condensate and the glasma

by McLerran, Larry (Nuclear Theory Group, Brookhaven Nat. Lab.)

Friday 2 Mar 2007, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

I argue that the high-energy limit of QCD is controlled by high-energy density gluonic matter characterized by high occupation number per state. This is the Colour Glass Condensate, and can be thought of as an ensemble of strong transverse classical and electromagnetic fields. Almost instantaneously after a collision, these fields change to purely longitudinal electric and magnetic fields which are independent of rapidity. This Glasma carries topological charge, and generates chiral symmetry breaking. The fields are unstable under small rapidity-dependent fluctuations generated by the field theoretical wave function at the initial singularity associated with the collision. Eventually these fields decay into gluons, and perhaps thermalize into a Quark Gluon Plasma. I show the correspondence of the 'Little Bang' of hadronic collisions with Big Bang cosmology. I also present some speculations that the distribution of Colour Glass Condensate density fluctuations may be generated by two-dimensional gravity.