Ultra-peripheral collisions - a new laboratory for high-energy physics

by Stanley J. BRODSKY (SLAC)

Friday 8 Mar 2002, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

Ultra-peripheral collisions at relativistic ion colliders, such as RHIC and the LHC, can provide an important new laboratory for testing fundamental aspects of QCD, especially coherent and diffractive phenomena. Ultra-peripheral collisions occur at large impact separations so that the colliding nuclei can remain intact after the collision. The reactions are driven by virtual photon and pomeron exchange. The coherent effective photon beam emitted by the relativistic nuclei is enhanced by a factor of the nuclear charge squared, so that the photon-photon collider luminosity is large. The effective photon-photon and photon-pomeron colliders have centre-of-mass energies up to 200 GeV for heavy ion collisions at the LHC. I will survey some of the interesting theoretical and phenomenological aspects of this field, including Higgs production, diffractive jet production, the novel effects of colour transparency in hard pomeron interactions, charge and spin asymmetries, gluon shadowing phenomena, planar correlations, vector meson interferometry, heavy quark production, nuclear capture processes, and the origin of nuclear shadowing in QCD.