Professor Peter Daniel Meyers, who transitioned to emeritus status on July 1, 2024, has graced the Department of Physics for forty years as an outstanding undergraduate and graduate teacher, curriculum innovator, experimental physicist, and highly sought-after high-energy physics adviser to the National Laboratories and the U.S. Department of Energy. 

Inspired by his physics teacher at John Marshall High School in Los Angeles, Peter left for Harvard University in 1971 and graduated with a bachelor of arts in physics in 1975. For graduate study, he chose the University of California, Berkeley, supported by a National Science Foundation Graduate Fellowship. He earned his Ph.D. in 1983 for a definitive experimental study at the new Fermi National Accelerator Laboratory (Fermilab) of deep-inelastic muon scattering to measure the quark structure of neutrons and protons. Coincidentally, both his undergraduate mentor, Lawrence Sulak, and his Ph.D. adviser, Mark Strovink, had been outstanding Ph.D. students of Princeton Nobelist Val Fitch. The stage was set.

Peter came to Princeton as a research associate in 1984 to join professors A.J. Stewart Smith and Frank Shoemaker and assistant professors William Louis and Daniel Marlow, who had just started designing an experiment at Brookhaven National Laboratory (E787) to test the relatively new Standard Model of particle physics, in collaboration with groups from Brookhaven National Laboratory and TRIUMF laboratory in Vancouver, Canada. Specifically, they would search with sufficient sensitivity (ten thousand times better than previous experiments) to discover the extremely rare decay mode of the K+ meson into a pi+ meson, a neutrino and an antineutrino, predicted by the Standard Model to occur only once in every ten billion K+ decays—or to discover new physics, should they measure a higher rate. After several upgrades to the detector and accelerator, the search bore fruit in 1997, confirming the Standard Model at an unprecedented level. To achieve his extraordinary sensitivity while beating down the backgrounds, Peter and his students created a new “blind analysis” technique to avoid biasing the results, which is now a standard practice throughout high-energy physics experiments. 

Peter advanced over the years to become leader of the Princeton group as the experiment closed in on the discovery measurement, by which time the experiment had grown into a large international collaboration including several Japanese institutes. Quoting one of E787’s founders, “Peter Meyers was a major intellectual force in the development and the conduct of the E787 experiments, and I can think of no other single participant who deserves more credit for its success.” We point out that the E787 measurement reigned supreme for twenty-five years before being superseded by a massive experiment at CERN, in Geneva, Switzerland. 

When E787 was completed in 1997, Peter joined William Louis, now at Los Alamos National Laboratory, and others on the Mini Booster Neutrino Experiment (MiniBooNE) at Fermilab to search for “sterile” neutrinos hinted at in a previous experiment, manifesting as oscillations of the well-known muon neutrino. Peter and Princeton engineer William Sands designed and supervised the construction of the four-story detector. Then, with students and postdocs, Peter performed the analysis that ruled out the presence of any additional neutrinos to the three in the Standard Model.

Moving on from MiniBooNE in 2007, Peter became interested in the missing “dark matter” thought to compose twenty percent of the energy equivalent of the universe and joined with a Princeton nuclear physics group and Italian institutes to form the DarkSide-50 experiment at the 5,000-feet-underground Gran Sasso National Laboratory near L’Aquila, Italy, to search for weakly interacting massive particles (WIMPs). Characteristically, Peter took major responsibilities that exploited the technical strengths of the Princeton high-energy group: the R&D and design of the dark-matter detector, a time projection chamber filled with liquid argon as a target, and oversight of the analysis of the multiyear data set that found no signal, setting the best upper limits on WIMP-argon scattering at the time. 

Peter ranks among the department’s best teachers of all time, on par with such legends as Aaron Lemonick, James Peebles, and Sam Treiman. His unusual talent spreads across the whole spectrum of academia: undergraduate and graduate courses, research talks, modernizing curricula, involving undergraduates in research, and supervising Ph.D. theses. He also did an outstanding job serving as director of undergraduate studies and director of graduate studies. He leads by example and hard work. Although he is demanding, students appreciated his dedication and gave him rave reviews. The following comes from the citation for his 1991 President’s Award for Distinguished Teaching, written by Harold T. Shapiro, President, Emeritus: “Professor Peter Meyers … is a distinguished research scientist, winner of a Presidential Young Investigator Award [from the National Science Foundation], and an outstanding teacher. His ability to convey the lessons—and beauty—of physics is demonstrated in graduate seminars, as well as in freshman physics courses. Whether he is discussing the development of a new quantum mechanics sequence in research symposia or leading students through a review session, he exhibits an unusual talent for opening students’ eyes and stretching their minds.” 

Beyond Princeton, national high-energy physics organizations have continually leaned on Peter for his thoughtful advice. He has served on various panels for the U.S. Department of Energy, the National Science Foundation, and the American Physical Society, most notably as a member of the High Energy Physics Advisory Panel (HEPAP), the prime advisory group for high-energy particle physics, and as the two-term chair of the Fermilab Physics Advisory Committee, which recommends which experiments should be approved to run at the prime U.S. accelerator laboratory. He was also elected to the Council of the American Physical Society as division counselor for particles and fields.

Over his career, Peter has received several honors and awards from Princeton and the particle physics community, among them his five-year Presidential Young Investigator Award from the National Science Foundation, the Princeton President’s Award for Distinguished Teaching, and the Princeton Undergraduate Engineering Council Teaching Award, which he won twice. He was elected to fellowship in the American Physical Society in 2002 “for contributions to rare kaon decay experiments, service, and leadership in the particle physics community, and for communicating the excitement of the field to expert and non-expert alike.”

Much of Peter’s success stems from his personal character. He insists on high standards in everything he does and persuades others to do the same, going out of his way to help them achieve their potential. This practice carries over to his research, where he has often helped colleagues understand and solve difficult problems in their parts of his experiments while eschewing credit for himself. Time and again people have commented along these lines: “Meyers and X make [or would make] a formidable team.” The invariant in these statements is Meyers.

Written by members of the Department of Physics faculty.