The ultrarelativistic heavy ion collison program at the BNL AGS and CERN SPS has underlined the usefulness of two-particle correlation studies in nuclear physics in providing information on the space-time geometry of the collision. Following a brief survey of the accomplishments of the ultrarelativistic heavy ion program, this talk will review the basic physics of intensity interferometry, and its current applications in high-energy nuclear physics as well as in trapped atomic systems. The technique was born in the 1950's, when Hanbury Brown and Twiss showed that one could measure the angular sizes of astronomical radio sources and stars from correlations of signal intensities (not amplitudes) in independent detectors. Their correlation experiments demonstrating quantum bunching of photons in incoherent light beams were seminal in the development of quantum optics. The effect is one of the few measurements in elementary particle detection that is sensitive to the wave mechanics of the produced particles.

ANL Physics Division Colloquium Schedule