Monday, January 26, 2009 Joint Physics Colloquium, 4:30 PM, 104 Thaw Hall, PITT

Prof. Andrzej Czarnecki

University of Alberta

"Polyelectrons and Exotic Atoms"

Abstract:

Polyelectrons are bound states of a few electrons and positrons.  The simplest example is positronium.  Its negative ion (two electrons and a positron), as well as a four-body dipositronium molecule have also been discovered and are the subject of on-going experiments.  Among their goals is the creation of larger polyelectrons to study the Bose-Einstein condensation of positronia and a gamma ray laser based on stimulated annihilation.

In this talk, I will review effective field theory methods used to determine precise properties of three- and four-body polyelectrons.  I will also show other examples of how exotic atoms provide information about fundamental interactions, and how methods originating in high-energy theory help determine their properties.