Gregg Franklin-Dept of Physics - Carnegie Mellon University

Gregg Franklin

Professor, Physics

Office: Wean Hall 8410
Phone: 412-268-2743
Fax: 412-681-0648


Ph.D., Massachusetts Institute of Technology


Research in medium energy physics explores the boundary between nuclear and particle physics. As part of the Carnegie Mellon University Medium Energy Group, Prof. Franklin is involved in an experimental program exploring the constituents of neutrons and protons using high-precision electron scattering at the Thomas Jefferson National Accelerator Laboratory (JLab). In some of the experiments, a high-energy beam of polarized electrons is used in measurements that achieve accuracies of one part in a million. These experiments determine the strength of the parity-violating weak interaction and this information is used to separate out the contributions of up-, down-, and strange-quarks (and their anti-particle partners) to the properties of the proton and neutron. Other experiments use polarized targets to provide additional links between the electromagnetic properties of nucleons and their constituents.

The Medium Energy Group is known for its work in detector development. Prof. Franklin is currently overseeing the design and construction of a new hadron calorimeter that will be used in a suite of experiments as part of JLab's SuperBigbite spectrometer program. This program will take advantage of JLab's energy-upgrade, a new large-acceptance spectrometer, and new detector packages to lend insight into the quark-structure of nucleons. The Medium Energy Group is also contributing to the upgrade of JLab Hall A's Compton Polarimeter. This device is designed to use the known spin-dependence of electron-photon scattering to determine the spin-polarization of the JLab electron beam to an accuracy of better than 1%.

Selected Publications