Experiments in meson spectroscopy test critical aspects of the standard theory of the strong nuclear force. Although they only live for a short time before they decay, mesons provide a unique laboratory for the study of the strong force because they are the simplest quark configuration, just a one quark and one antiquark. The GlueX experiment is a major new initiative being undertaken at Jefferson Lab in Newport News, Virginia using polarized photons from the CEBAF electron accelerator to search for a new class of excitations known as exotic mesons. Although exotics were predicted based upon the standard theory over 20 years ago, conclusive experimental evidence for their existence has not yet been established. The P.I. is a member of the governing board of the GlueX experiment and has specific responsibility in the design and construction of the polarized photon source. A preliminary step towards the larger goals of GlueX was the Radphi experiment was constructed study the decays of a known meson, the phi(1020). The phi itself is not exotic, but some evidence pointed to the possible exotic nature of two other mesons at around the same mass, the a0(980) and the f0(980). Radiative decays of the phi to these scalars provide an important test of this hypothesis. The experiment collected its data during a 60-day run in summer 2000, and is in the final stages of data analysis. The P.I. is also involved in the Qweak experiment at Jefferson Lab, which undertakes a precise measurement of the weak charge of the proton as a search for physics beyond the Standard Model. In this project he has shared responsibility for the Compton-backscatter electron polarimeter.
