Simon Peter Rosen, a leading theoretical physicist and manager of physics research programs, died on 13 October 2006 at his home in Rockville, Maryland, after a courageous three-year battle with pancreatic cancer. A noted authority on the weak interactions, Peter was also a gifted teacher, a graceful writer, and an effective spokesman for physics.
Born on 4 August 1933 in London, Peter studied at Merton College, Oxford University, and received a BA in mathematics in 1954 and an MA in 1957. At the Clarendon Laboratory at Oxford, he completed a DPhil in physics in 1957, with a dissertation entitled “Double Beta Decay.” He then went to the US, where he joined Henry Primakoff at Washington University in St. Louis, Missouri.
With Primakoff, Peter laid the foundations for the physics of neutrinoless double beta decay. Observation of this process would establish that neutrinos are their own antiparticles and that lepton number is not conserved. In an important insight dating from just after the discovery of parity violation in 1956, they realized that maximum parity violation would greatly suppress neutrinoless double beta decay, making it more elusive than previously thought. But with the discovery of neutrino mass in the late 1990s, elementary particle physicists recognized the importance of searching for this rare decay. Numerous experiments designed to have the very high sensitivity that will be required are currently being developed.
Peter’s many contributions to our understanding of the weak interactions included work with James Gelb on the implications of the Mikheyev-Smirnov-Wolfenstein effect for neutrino flavor change in the Sun. With other collaborators, Peter analyzed possible consequences of so-far hypothetical very heavy neutrinos and devised ways to determine directly the space-time structure of the weak neutral current.
In 1962 Peter joined the faculty at Purdue University, where for two decades he carried out an active research program in theoretical physics. He became a naturalized American citizen in 1972. He was appointed an associate division leader at Los Alamos National Laboratory in 1983, with responsibility for the research program in nuclear and particle physics. Named dean of science at the University of Texas at Arlington in 1990, Peter led six science departments and established a strong and thriving high-energy physics group in the physics department there. He was a visiting scientist at the nearby Superconducting Super Collider Laboratory and worked with other universities to encourage a strong physics research community in northern Texas.
From 1997 to 2003, Peter was associate director of the Office of Science in the Department of Energy, with responsibility for DOE’s extensive high-energy and nuclear physics research programs and facilities. Major advances during his term in office included the discoveries of dark energy and neutrino oscillations, startup of the B Factory at SLAC and the Relativistic Heavy Ion Collider at Brookhaven National Laboratory, a major upgrade of the Tevatron at Fermilab, and US participation in the Large Hadron Collider project at CERN.
Peter was elected a fellow of the American Association for the Advancement of Science in 1992. In 2000 he was named professor emeritus of the University of Texas at Arlington and was cited for “years of excellence in teaching, internationally acclaimed research, and administrative service to the University.”
While undergoing intensive cancer treatments from 2003 to 2006, Peter continued his efforts on behalf of physics as long as his health allowed and served as senior science adviser to the director of DOE’s Office of Science. In 2005 he led the Office of Science’s observance of the World Year of Physics; his contributions included writing and speaking about physics, such as a lecture he gave at DOE entitled “Einstein Made Easy: Special Relativity at the Heart of Office of Science Programs.” He helped provide DOE support for the American Physical Society’s World Year of Physics activities and for “Einstein’s Big Idea,” a PBS NOVA program about special relativity. Peter understood the value of humanizing science for the general public. For him, science and humanity were intimately connected.
During the last year of his life, Peter renewed his close and direct ties to the physics community by managing the theoretical particle physics program at NSF. Once again he could be a steward of the field and nurture young theorists just starting their careers. In early 2006 he also gave his last two invited talks at a neutrino conference in Venice. In the summer he wrote an eloquent tribute to Nobel laureate Ray Davis Jr, whom he called the “discoverer and grand pioneer of the solar neutrino problem.” It was published in the CERN Courier in September 2006, just a month before Peter died.
Peter was a wonderful man with a gentle soul. He had an appealing low-key charisma and charm, an engaging courtly manner, and a cheerful, quiet sense of humor. His idea of making an angry retort was to write a clever, barbed letter and then, instead of mailing it, to bury it in one of his desk drawers.
A highly accomplished theoretical physicist, a generous and supportive colleague to physicists around the world, and a wise manager of research programs, Peter has had a broad and substantial impact on physics. He will be sorely missed.
