The Gregory Breit Centennial Symposium

This book contains the proceedings of the Gregory Breit Centennial Symposium. The legacy of Breit to atomic, nuclear and particle physics is discussed vis- -vis modern developments in these fields. Among other subjects, the present status of the Breit interaction in atomic physics and of the nucleon-nucleon interaction are reviewed. The second part of the book contains a more in-depth presentation of the status of modern nuclear physics, from relativistic heavy ion physics to nuclear structure physics and nuclear astrophysics. The recently confirmed discovery of supersymmetry in nuclei is also discussed.

Paul Adrian Maurice Dirac (1902-84) is one of the icons of modern physics. His work provided the mathematical foundations of quantum mechanics. He also made key contributions to quantum field theory and quantum statistical mechanics. He is perhaps best known for formulating the Dirac equation, a relativistic wave equation which described the properties of the electron, and also predicted the existence of anti-matter. The Dirac Centennial Symposium commemorated the contributions of Dirac to all areas of physics, and assessed their impact on frontier research. This book constitutes the proceedings of the symposium, containing articles by Leopold Halpern, Pierre Ramond, Frank Wilczek, Maurice Goldhaber, Jonathan Bagger, Joe Lykken, Roman Jackiw, Stanley Deser, Joe Polchinski, Andre Linde and others. A special contribution from Dirac's daughter Monica Dirac presents a portrait of Paul Dirac as father and family man.

A recollection of life in the workshops where nuclear bomb components were constructed during the Manhattan Project.

This book traces the evolution of Atomic Physics from precision spectroscopy to the manipulation of atoms at a billionth of a degree above absolute zero. Quantum worlds can be simulated and fundamental theories, such as General Relativity and Quantum Electrodynamics, can be tested with table-top experiments.

The exchange between physics and metrology is always fascinating and exciting. Many are the open problems in physics that call for extremely precise standards, many are the advances in metrology made possible by a deep and assiduous study of the underlying physics. One has just to think of the enormous sophistication required in the measurements of some absolute quantities such as the Avogadro, the gas, or the gravitational constants. It is also worth noticing that not only the units of a metrological system are interrelated through the fundamental constants, but also the latter find their full significance when they are determined through the most exacting metrological experiments. Over the past decade many improvements took place and these are discussed in this book; from one side the old caesium SI second definition has found a new realisation, with the “fountain” approach, replacing the classical thermal atomic beam. The use of “cold” atom techniques, in which bunches of inert atoms are collected, slowed down, and cooled, has opened a number of new and unexpected avenues for metrology and fundamental constants; one of these possibilities being the atom interferometry. Another important “quantum jump” was the demonstration of the possibility of performing a direct frequency division in the visible, using ultra short femtosecond pulses. In addition, the possibility of “counting” electrons or photons gave a fundamental support to the development of single-electron capacitance standards and to new scenarios in the absolute calibration of photo-detectors.

In August/September 2001, a group of 75 physicists from 51 laboratories in 15 countries met in Erice, Italy to participate in the 39th Course of the International School of Subnuclear Physics. This volume constitutes the proceedings of that meeting. It focuses on the theoretical and phenomenological developments in string theory, as well as in all the other sectors of subnuclear physics. In addition, experimental highlights are presented and discussed.