David W Hertzog

Education

• Ph.D., Physics, College of William & Mary, June 1983

Biography

Professor Hertzog received his bachelor's degree in physics from Wittenberg University in 1977, and his Ph.D. in physics from the College of William and Mary in 1983. He joined the Department of Physics at the University of Illinois as an assistant professor in 1986.

Professor Hertzog's work includes a precision measurement of the muon's anomalous magnetic moment (or "(g–2)" factor) in a major experiment at Brookhaven National Laboratory, which represents a substantial branching out from hadronic to electroweak physics and correctly reflects his broad physics interests. Professor Hertzog was also the leader of one of four independent analysis teams to examine the experimental results, which provided the first crack in the standard model in 30 years . He is co-leading a new experiment at Fermilab, with the aim of improving the precision by more than a factor of 4 on the muon anomaly.

Professor Hertzog is also undertaking another major experiment at the Paul Scherrer Institute, where he and his collaborators are developing a new state-of-the-art instrument capable of performing high-precision and fundamental measurements of the muon. At the outset, the MuLAN Project (Muon Lifetime ANalysis) is aimed at a 1-ppm (part per million) measurement of the positive muon lifetime, t_m, resulting in a 20-fold improvement over previous efforts. This improvement in the precision of the muon lifetime leads to an increased precision in the determination of the Fermi constant, G_F, by the same amount.

He is also known for his invention of a novel lead-scintillating fiber electromagnetic calorimeter (termed the PbSciFi detector), which is cheaper to produce, provides higher resolutions, is significantly smaller, and is able to withstand 100 times more background radiation than other calorimeters in its class. He has also done prior significant work in antiproton physics, in particular hyperon-antihyperon production and the search for glueballs.

Professor Hertzog is also one of the most able and most highly regarded instructors in our department; he has won nearly every teaching award given by the College of Engineering at Illinois.

Research Statement

My current research focuses on precision measurements of fundamental importance in subatomic physics.

g–2: Our group is engaged in a sub-ppm measurement of the muon's anomalous magnetic moment (g–2). The results of this experiment, when compared with precise theoretical calculations, are capable of revealing physics beyond the Standard Model attributed to SUSY particles of high mass, to structured intermediate vector bosons, or to substructure of the muon itself.

MuLan: The Muon Lifetime Analysis (MuLan) experiment measures the positive muon lifetime, which provides the most precise determination of the Fermi coupling constant, one of the fundamental inputs to the standard model. Recent advances in theory have reduced the theoretical uncertainty on the Fermi coupling constant as calculated from the muon lifetime to a few tenths of a ppm. The remaining uncertainty on the Fermi constant is entirely experimental and is dominated by the uncertainty on the muon lifetime. The MuLan experiment employs an innovative pulsed beam, a symmetric detector, and modern data-taking methods to reduce the uncertainty on the muon lifetime to 1 ppm.

MuCap: The goal of the µCap experiment is a 1% precision measurement of the muon capture rate on the proton. From the capture rate, the pseudoscalar form factor, g_P, of the nucleon will be extracted with 7% precision. This basic quantity is predicted theoretically with high precision, but the experimental situation is quite controversial. The new experiment should yield an unambiguous value for g_P and a sensitive test of the chiral symmetry of QCD at low energies.

Selected Articles in Journals

• G.W. Bennett, et al.  (Muon g-2 Collaboration). Final report of the Muon E821 anomalous magnetic moment measurement at BNL. Physical Rev. D 73, 072003 (2006).
• D.W. Hertzog and W.M. Morse. The Brookhaven muon anomalous magnetic moment experiment. Ann. Rev. Nucl. Part. Sci. 54, 141-174 (2004).
• D. W. Hertzog. Muons: Particles of the moment. Physics World 17 N3, 29-34 (2004).
• G. W. Bennett, et al. (Muon g-2 Collaboration). Measurement of the negative muon anomalous magnetic moment to 0.7 ppm. Phys. Rev. Lett. 92, 161802 (2004).