Two-photon physics, i.e. photon-photon collisions in electron-positron colliders, a relatively new field in elementary particle physics, has become very popular in the last 20 years. Many experiments have been performed in this field, and the theoretical implications (in particular in quantum chromodynamics) have been studied in much detail. Nine international workshops devoted to two-photon physics have taken place between 1973 and 1992.This meeting was particularly timely, since a new generation of electron-positron colliders is presently being built or planned. These colliders will involve a large spectrum of beam energies, but their common characteristics should be a high particle flux (luminosity). This should allow for measuring many new phenomena as well as for studying known processes with much higher precision than before. Particularly promising is the prospect of building a dedicated high-energy photon collider; this should become possible using a laser technique allowing for the “conversion” of a linear electron beam into a photon beam.Over 60 physicists (both experimentalists and theorists), mainly from European countries (France, Britain, Italy, Germany, Russia, as well as Sweden and Switzerland), discussed these new possibilities at the above meeting. Over 30 talks were presented and many extended debates took place.

Because the two photon cross section is proportional to Z[sup 4], heavy ion colliders offer an unmatched luminosity. However, because nuclei have finite sizes, the photon spectrum is gradually cut off by a nuclear form factor. For RHIC, this cutoff occurs at a few GeV; below this energy, RHIC will have the highest[gamma][gamma] luminosity in the world when it turns on. In addition to the high rates, because Z[alpha][approximately] 0.6, the nuclear environment provides a window to strong field QED and new phenomena like multiple pair production. To study[gamma][gamma] physics, regions where the nuclei interact hadronically must be avoided; this leads to roughly a factor of two loss in usable luminosity. The rates expected by the Solenoidal Tracker at RHIC (STAR) collaboration will be given. Backgrounds will be discussed, along with several rejection techniques.

Recent experimental results in two-photon physics are reviewed. Possibilities for future experimentation at high [gamma][gamma] collision energies are discussed. 95 refs., 12 figs., 7 tabs.

From the early wave-particle arguments to the mathematical theory of electromagnetism to Einstein's work on the quantization of light, different descriptions of what constitutes light have existed for over 300 years. This book examines the photon phenomenon from several perspectives. It demonstrates the importance of studying the photon as a concept belonging to a global vacuum (matter-free space). The book explains the models and physical and mathematical descriptions of light and examines the behavior of light and its interaction with matter.