Associate 1997-98

Douglas H Beck


Quark Structure of the Proton

The particles that make up the atomic nucleus, protons, and neutrons, are themselves composed of particles called quarks and gluons. One of the main activities in modern physics is to understand how quarks and gluons combine together to make up protons and neutrons, in much the same way as the atom with its electrons and nucleus was studied early in this century. In contrast to the situation in the atom where the electron is attracted rather weakly to the atomic nucleus, the quarks in the proton have very strong forces of attraction. This leads to the appearance of pairs of additional quarks within the proton which materialize from these strong energy fields. In a series of experiments utilizing a beam of electrons scattered from proton targets, Professor Beck and his team will study the effect of these quark pairs, and hence of the strong forces that bind the quarks together. Many common systems studied in physics such as metals or proteins are composed of many particles that interact quite weakly; some of their most interesting behaviors such as superconductivity and living organisms result from cooperative or 'collective' effects. The purpose of these experiments is to broaden and deepen our understanding of the behavior of strongly interacting particles and move toward exploration of possible collective effects in these systems.