PROFESSOR DAVID W. HERTZOG
Department of Physics University of Washington
Box 351560, Seattle WA 98195
(206) 543-0839 begin_of_the_skype_highlighting(206) 543-0839end_of_the_skype_highlighting begin_of_the_skype_highlighting
College of William and Mary Ph.D., Physics 1983
Carnegie-Mellon University Research Associate 1983-86
University of Illinois Assistant Professor, Physics 1986-92
University of Illinois Associate Professor, Physics 1992-97
University of Illinois Professor, Physics 1997-2010
University of Washington Professor, Physics 2010-
Current research: I am involved in a series of high-precision experiments involving muons:
I am co-spokesman of New g-2 Experiment and also of the completed MuLan experiment. My colleague Peter Kammel is co-spokesperson of MuSun and MuCap. Our group is known for innovate work in developing various detectors, electronics, and analysis that enable highly precise experiments featuring muon physics. For a recent review of Precision Muon Physics, click here.
Honors and awards:
teaching and training (at Illinois) Developed new Modern Experimental
Physics Laboratory course featuring research-style data
recording, analysis techniques, report writing, and oral
presentations. Developed two-semester Introduction
to Physics Research/Senior Thesis course sequence to
prepare advanced undergraduates for physics careers.
Served on the design teams
for new introductory physics courses, which incorporate
active-learning pedagogy. Designed and implemented all new
laboratories for two semesters of algebra-based introductory
physics courses. Wrote The
Problem Solver for Physics 102 Discussion sections.
Developed Discovery Room for Practical
Physics: How Things Work course. Co-teacher for several years in the
Science literacy and public outreach: Founded and ran for two years the Saturday Physics Honors Program aimed at high school students, but also attended by the general public. Several invited talks to under-graduates and high-school physics teachers and public forums on muon g-2 experiments and more recently on The World's Greatest Scientific Instruments.
Ph.D. Students Supervised (academic research institution if applicable):
R. Tayloe (Indiana), S.A. Hughes, P.E. Reimer (ANL), J. Ritter, T. Jones, B. Bunker, F.E. Gray (Regis Univ.), C. Polly (Fermilab), D.B Chitwood, S. Clayton*,** (LANL), D. Webber, J. Crnkovic (BNL), B. Kiburg* (Fermilab), S. Knaack*(Wisconsin), M. Murray*
*co-supervised with P. Kammel;
**co-recipient APS Dissertation Prize in Nuclear Physics, 2009.
Postdoctoral Fellows Supervised:
P.G. Harris, S.A. Sekykh, G. Onderwater, F. Mulhauser, C. Ozben, R. McNabb, P. Winter, S. Kizilgul, P. Alonzi, J. Kaspar, K. Khaw
Some special papers of interest:
Precision Muon Physics, T.P. Gorringe and D.W. Hertzog, Prog. Part. Nucl. Phys. 84 (2015) 73-123. (pdf) This is a review of recent, current, and future experiments in muon physics cutting across atomic, nuclear and particle physics subfields.
Low-energy precision test of the standard model: a shapshot, D.W. Hertzog, Annalen der Physik, (2015) / DOI 10.1002/andp.201500167 (pdf). This is a brief review of experiments that are testing the SM using low-energy, techniques.
Final report of the E821 muon anomalous magnetic moment measurement at BNL; Muon g-2 Collaboration, G.W. Bennett et al., Phys. Rev. D 73, 072003 (2006) (pdf) This is the summary paper of the BNL experiment with final numbers from all runs.
The Brookhaven Muon Anomalous Magnetic Moment Experiment, David W. Hertzog and William M. Morse, Annu. Rev. Nucl. Part. Sci. 2004. 54:141-74. (pdf) This is an experimental overview for general readership.
Muons: Particles of the Moment (Physics World, March 04) My discussion of the muon g-2 experiment for non-experts in pdf at abot the time of the fun controversial issues in theory and experiment.
Description of Current Research
My current research focuses on
precision measurements of fundamental importance in subatomic
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. Our final measurement, from the Brookhaven E821
Experiment, is more than 3 standard deviations from the current
(2015) Standard Model expectation and the result has caused a
significant buzz in the theoretical community. engaged in a new
measurement at Fermilab to achieve
much high precision as the muon
anomaly remains an important low-energy test of new physics and
refining the result will be critical to aid in elucidating the
nature of any new physics scenarios revealed at the LHC.
Our UW group has been a leader in the detector development, the
precision field measuring equipment, the beam delivery
calculations, and in the overall organization and leadership of
the experiment. the UW group has several graduate
students, postdocs, and senior research physicists
involved. The experiment is scheduled to start data taking
in early 2017. [Selected
This experiment, led by Kammel,
follows naturally on the development from MuCap
(below) and utilizes much of the same basic equipment. What is
new is a cryogenic high-pressure deuterium TPC, operated in
ionization mode, that can locate stopped muons
and provide high resolution on the deposited energy. The
motivation for μd capture is based on measuring the rate of the
semileptonic weak process μ + d --> n + n + νμ . The process can be described up
to a low-energy constant (LEC) in various modern effective field
theoris. Similarly, so can
several similar fundamental reactions of astrophysics interest,
such as solar pp fusion and the ν+d reactions
as observed by the SNO experiment.
A precise measurement by MuSun will
fix the common LEC and will therefore help, as theorists have
stated, calibrate the sun.
We have recently completed data taking of the full data set;
some systematic studies remain. The analysis is centered
at UW with several graduate students and postdocs involved.
Mu2e: The Mu2e Experiment at Fermilab is a major new effort for the
laboratory that seeks to measure the Standard Model forbidden
direct conversion of a muon to an
electron (charged lepton flavor violation; cLFV)
to a single event sensitivity below 1 part in 1016! There
are many hints that cLVF should
occur at this level, or else severe constraints will be placed
on many popular SM extensions. The idea for the experiment
has been around for a very long time; the realization, of
course, is difficult. Now, Fermilab
-- blessed by supportive external committees and the DOE -- is
investing funds to build the experiment. It requires a
series of superconducting solenoids for the production,
transport, and detection of muons
and converted electrons. The Collaboration is in an active
design phase with a timetable for first running not before about
2020. Our group expertise on muon
capture and calorimeter and other detector development fits
nicely into the needs of Mu2e and we ramp up our involvement
over the coming years, subject to g-2 data taking. To
date, we organized a muon capture
test at PSI of candidate Al and Ti targets to measure critical
ejected proton and neutrons, which will affect the detector
design. These efforts are ongoing.
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. This experiment took place at the Paul Scherrer Institute, Switzerland. We completed data taking, analysis, and several well-deserved Ph.D. theses. We proudly achieved our exact proposal goal of 1.0 ppm final precision, measured twice in blind experiments. The Fermi constant, so obtained, has a precision of 0.5 ppm. Our final paper is here. The photo at the right shows some of us having prepared the soccer-ball-shaped detector for shipping to PSI.
goal of the MuCap experiment is a 1% precision measurement of
the muon capture rate on the
proton. From the capture rate, the pseudoscalar
form factor, gP,
of the nucleon will be extracted with 7% precision. This basic
quantity is predicted theoretically with high precision, but the
experimental situation was quite controversial. The first round
of our experiment led an unambiguous value for gP and a strong
confirmation of the chiral symmetry of QCD at low
energies. The success was based on the novel idea of
capturing negative muons in
ultra-pure hydrogen gas (not liquid) and, equally importantly,
instrumenting the stopping volume in the manner of a time
projection chamber (TPC). My colleague Peter Kammel invented
the idea and led the effort from its inception. Two MuCap Ph.D. students were the co-winners
of the APS Nuclear Physics Dissertation prize for the earliest
phase of the work, and two others have since graduated on
refinements. The final
paper demonstrated that the theory is right, a very