Gregg B. Franklin
Emeritus Professor of Physics
Nuclear & Particle Physics
Quark Interaction Experiment
Wean Hall 8018
Education & Professional Experience
Ph.D.: Massachusetts Institute of Technology (1980)
B.S.: University of Washington (1976)
Honors and Awards:
Paul M. Higgs Prize (1976)
Head, Physics Department, Carnegie Mellon University, 2008–2013
Professor of Physics, Carnegie Mellon University, 1997–
Visiting Professor, University of Washington, 1994–1995
Faculty, Carnegie Mellon University, 1984–
Research Associate, Carnegie Mellon University, 1981–84
Research Associate, MIT, 1980–81
Research Interests
Research in Medium Energy Physics explores the boundary between nuclear and particle physics. As part of the Carnegie Mellon University Quark Interactions 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 Quark Interactions 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
Gregg B. Franklin, The APEX experiment at JLab. Searching for the vector boson A' decaying to e+e-, EPJ Web Conf. 142, 01015 (2017)
A. Rakhman et al., A high-finesse Fabry-Perot cavity with a frequency-doubled green laser for precision Compton polarimetry at Jefferson Lab, Nucl. Instrum. Meth. Phys. Res. A 822, 82 (2016)
J. Benesch, G.B. Franklin, BP. Quinn, K.D. Paschke, Simple modification of Compton polarimeter to redirect synchrotron radiation, Phys. Rev. ST Accel. Beams 18, 112401 (2015)
D. Parno et al., (CMS Collaboration) Precision measurements A1n in the deep inelastic regime, Phys. Lett. B744, 309 (2015)
M. Posik et al., Precision measurement of the neutron Twist-3 matrix element d2n: Probing color forces, Phys. Rev. Lett. 113, 22002 (2014)
D. Wang et al., Measurement of parity violation in electron-quark scattering, Nature 506, 67 (2014)
S. Abrahamyan et al., New measurements of the transverse beam asymmetry for elastic electron scattering from selected nuclei, Phys. Rev. Lett. 109, 192501 (2012)
Z. Ahmed et al., New precision limit on the Strange vector form factors of the proton, Phys. Rev. Lett. 108, 102001 (2012)
M. Friend et al., Upgraded photon calorimeter with integrating readout for the Hall A Compton polarimeter at Jefferson Lab, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 676, 96 (2012)
M. Friend, G.B. Franklin, B. Quinn, An LED pulser for measuring photomultiplier linearity, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 676, 66 (2012)
D. Androić et al., Transverse beam spin asymmetries at backward angles in elastic eectron-proton and quasielastic electron-deuteron scattering, Phys. Rev. Lett. 107, 022501 (2011)
D. Androić et al., The G0 experiment: Apparatus for parity-violating electron scattering measurements at forward and backward angles, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 646, 59-86 (2011)
S. Riordan et al., Measurements of the electric form factor of the neutron up to Q2=3.4 GeV2 using the reaction 3He(ee'n)pp, Phys. Rev. Lett. 105, 262302 (2010)
J. Parker et al., Weak decays of Λ4He, Phys. Rev. C 76, 035501 (2007)
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ORCID Researcher ID