JLab: Probing Hadronic Physics with Electrons and Photons

Precision measurements of the structure of nucleons and nuclei in the regime of strong interaction QCD are now possible with the availability of high current polarized electron beams, polarized targets, and recoil polarimeters, in conjunction with modern spectrometers and detector instrumentation. The physics at JLab will be highlighted using two recent measurements of general interest. The ratio of the proton electric to magnetic form factors indicates the importance of the role of angular momentum in the structure of the nucleon. The existence of 5-quark configurations in the ground state wavefunctions of hadrons is confirmed by a narrow peak attributed to an exotic baryon with strangeness S=+1. These and other examples will be used to illustrate the capabilities and focus of the experimental program at JLab.Comment: V Latinamerican Symposium on Nuclear Physics, Santos, Brazil (Sept 1-5, 2003) 4 pages, 4 figure

Circuit switches latching relay in response to signals of different polarity

A circuit using one power supply and two storage capacitors, which may be separately discharged in opposite directions through a relay in response to change in polarity of a signal, is described

Polarity sensitive circuit Patent

Electric circuit for reversing direction of current flo

Review of Recent Jlab Results

High quality polarized electron beams at Jefferson Lab make possible precision measurements of hadronic properties in the regime of strongly interacting QCD. We will describe a few programs at Jefferson Lab that are making measurements that link the basic static properties of hadrons to their quark sub-structure. For example, parity-violating electron proton elastic scattering probes the spatial distribution of strange quarks in the nucleon. The nucleon-Delta transition form factors give us information about the deformation of nucleons and Deltas. Finally, new high statistics measurements of photons scattering off proton and deuteron targets are used to set upper limits on the production of exotic baryons with strangeness S=+1. These examples will be used to illustrate the capabilities and focus of the experimental program at JLab.Comment: Contribution to XI International Conference on Hadron Spectroscopy, 4 figure