Intermediate Energy Physics at Jefferson Lab and IUCF

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9901529DytmanThe University of Pittsburgh Intermediate Energy group has twomajor projects underway. The first project is centered aroundthe CEBAF Large Acceptance Spectrometer (CLAS) at the JeffersonLab. We will use this newly commissioned detector for a widerange of studies of the basic components of matter- the proton and neutron. The microscopic structure of the proton has been studiedfor many years, but its richness has made a quantitative understanding difficult to obtain. Our basic goal is to learn as much as possible about the resonant intermediate states that are rearrangements of the quarks and gluons in the proton, i.e. the spectroscopy of the baryon states. The basic reaction has photon or electron beams impinging on a liquid hydrogen target. With CLAS, we can then examine essentially all of the many final states simultaneously. Our group will study final states that include eta and eta-prime particles because limited data to date have shown unusual and interesting behavior. The wide coverage will allow more complete theoretical studies of the quantum mechanical processes through which the final states develop. We also working on a phenomenological analysis program to extract the spectroscopic information. Our second project uses the Indiana University Cyclotron Facility (IUCF) Cooler Ring to produce pions in proton-proton collisions. Our previous experiments found a strong sensitivity to the way the pion couples to the proton, one of the fundamental features of the strong interaction in nuclei. The present experiments extend the study to spin variables at higher energy.