Alumna Pursuing Fourth ODU Degree

By Melissa Watkins Starr (M.A. ’05)

Doctoral student Sharon Careccia ’92, ’01 (M.S. ’03) reported the preliminary results of her ongoing research in Old Dominion’s physics department at two major conferences last year: the Gordon Research Conference in Tilton, N.H., and the American Physical Society’s Division of Nuclear Physics Conference in Oakland, Calif. Careccia, who works under physics department chair Gail Dodge, has conducted research on neutron structure, with a focus on neutron spin structure.

Since physicists now know that the fundamental particles in the universe are not protons, electrons and neutrons, as once believed, they are seeking to understand how smaller particles called quarks come together to form the nuclei of atoms. Careccia uses deuteron, an isotope of hydrogen, and a continuous electron beam accelerator at Jefferson Lab in Newport News to conduct her research.

“I basically showed that if we scatter electrons off a neutron, it will excite the neutron and create a higher mass resonance state,” she said. “When the neutrons de-excite, I get a meson, which is a quark/anti-quark pair. In the particular channel I’m looking at, where an electron hits a neutron, we get excited resonances that de-excite into a proton and a negatively charged pion. Studying the end states gives us insight on the spin structure of the struck neutron. When it calms down, the energy transferred to the neutron from the electron excites it into a new particle.

“This was predicted by Einstein,” Careccia noted. “Energy and mass are not the separate things we once thought they were. Given enough energy, you create a new particle. Now we know from scattering experiments that we have created new particles.”

Careccia, who began her career in the field of art, holds bachelor’s degrees in both engineering technology and physics, and a master’s in physics, all from ODU. She will finish her doctorate this year and hopes to teach physics at a college or university and continue her research.