Initial-state CGC effects

• Initial conditions at RHIC: high-energies + large nuclei

  • Values of small-x: xBj= 2pT/√s <<1
  • Large gluon densities

• Colliding nuclei described via a colored

• highly saturated gluonic wave-function

• (“Color Glass Condensate”).

• "Classical" approach valid around “sat. scale”: Qs~1.5 GeV/c

• Particle production via glue-glue collisions:

• Extension to pT > Qs (“geometric scaling”)

• via quantum evolution.

• Expected result: gluon fusion at low x leads to an effective depletion of the number of partonic scattering centers in the initial state.