Special Colloquium, Thursday, January 22, 2004

QCD at High Energy

Yuri Kovchegov

University of Washington

We will discuss the exciting new results in our theoretical understanding of quantum chromodynamics (QCD) at high energies. We will argue that at very high energies hadronic and nuclear wave functions become very dense dominated by huge numbers of sea gluons and quarks. This high parton density leads to extremely strong non-perturbative gluonic fields making the corresponding dynamics highly nonlinear. At the same time the strong coupling constant becomes small allowing for an analytical description of the hadronic and nuclear wave functions and corresponding scattering processes. We will show that when gluon density becomes very large gluons begin to recombine leading to saturation of gluon distributions. The partonic matter in the saturated hadronic and nuclear wave functions is also known as Color Glass Condensate (CGC). We will discuss the implications of saturation/Color Glass Condensate physics for deep inelastic scattering (DIS) experiments at HERA and eRHIC and for the studies of quark-gluon plasma (QGP) in heavy ion collisions at RHIC and LHC. We will show new experimental data obtained in dAu collisions at RHIC and argue that it confirms the theoretical expectations based on saturation/Color Glass Condensate picture.

10:30 a.m., Smith Laboratory, Room 1094