Diffraction at RHIC

Abstract

The relativistic heavy ion collider (RHIC) offers many opportunities to study diffraction in pp, pA and AA collisions. Because both proton beams can be polarized, RHIC offers the unique possibility of studying polarization effects in diffraction. We will introduce diffraction at RHIC and present three compelling physics topics: hard diffraction with polarized beams, identification of exotic mesons (non-qq̄ states) in double-Pomeron collisions and using diffraction to measure the low-x gluon density in pA collisions, testing models of gluon saturation and the coloured glass condensate. This note developed from discussion at a workshop on ‘Diffraction and Glueball Production at RHIC’ at Brookhaven National Laboratory, 17–18 May 2002.