The largest physics fair in the world took place in Atlanta, Ga., March 15 - 26. Nearly 30 Jefferson Lab staff attended the centennial celebration of the American Physical Society (APS), presenting papers, participating in seminar discussions and attending the large exhibition chronicling the history of the APS.

The Division of Nuclear Physics Display presented information about JLab, RHIC, science education, applications of nuclear science and other nuclear physics fields.

Nearly 11,000 physicists (almost double the projected attendance), including 50 Nobel laureates, from around the world gathered at the Georgia World Congress Center for the APS meeting. In addition to sessions where physicists discussed things like "Electron Deuteron Elastic Scattering in a Simple NN Potential with Excluded Spurious States: Non-relativistic Calculations," the event also featured public events on the physics of beer, baseball, dance, brass musical instruments and Star Trek. Nobel winner Stephen Hawking gave a free public lecture on "The Universe in a Nutshell" at the Atlanta Civic Center.

Ten papers dealing with the results of nucleon-resonance excitation investigations conducted in Hall B were presented during the APS meeting. The Hall B experiments focused on three of the six known flavors of quarks: up, down and strange. Scientists are attempting to better comprehend the interactions between those quarks and the gluons holding them together to form protons and neutrons.

The results of Hall A investigations to determine deutronic structure were also presented at the meeting, as was a paper detailing the outcomes of Jefferson Lab's nucleon-form-factors related investigations. Results determined that the quark-carried charge distribution on a proton is larger than its magnetic distribution. Currently, the reason for the disparity is not known or understood. "Everybody assumed that both the charge distribution and the magnetic distribution were the same," said Hall A leader Kees de Jager. "So the theorists didn't pay much attention. Now that we know both are different, we have to find an explanation. Our work has definitely generated a lot of interest."

While the findings do not appear to challenge the basic tenets of current quantum chromodynamics theory - theory can't yet account for whatever underlying mechanism is responsible for the size difference in charge and magnetic distribution. In any case, the Lab's findings are generating both attention and enthusiasm among theoreticians and experimentalists. Researchers at the Lab and elsewhere will have their hands full trying to solve the mystery.

Additional form-factor experiments have been planned which will probe the proton charge distribution within even smaller spatial resolution.

Syracuse University professor of physics Paul Souder, a primary Hall A Proton Parity Experiment architect and co-spokesman for the international HAPPEX team presented the results of their first round of HAPPEX experiments during a poster session at the meeting. "We were able to rule out the more exotic measurements of the contributions of the strange-quark content of the proton," said John Michael Finn, HAPPEX co-spokesman and College of William and Mary physics professor. "We have plans for future measurements to look at other nuclei. The eventual goal is to map the strength, the flavor currents in the nucleus; and how much up, down and strange quarks contribute to the nucleon's structure."

A second, more stringent round of HAPPEX experiments are slated to start at JLab this month and run through August. "We now have the tools to take HAPPEX further," Finn said. "We'll be conducting a systematic and rigorous program, but on the scale of years rather than decades."

Cynthia Keppel, JLab staff scientist and assistant professor or physics at Hampton University, presented results of an experiment delving into the phenomenon known as quark-hadron duality.



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