Obituary of Peter Barnes (1937-2011)

Peter David Barnes, a pioneer in the field of medium-energy nuclear physics, died of non-Hodgkin’s lymphoma on March 25 at his home in Amagansett, Long Island. He was 73. During his fruitful career he was among the leaders in the use of higher energy particle beams to explore novel aspects of nuclear physics. He also spent a productive decade as Director of the Los Alamos Meson Physics Facility and as Head of the Physics Division at Los Alamos.

Peter completed undergraduate work at Notre Dame in 1959. His PhD research, in the area of nucleon transfer reactions, was completed at Yale University in 1965 under the direction of Charles K. Bockelman. Subsequently he enjoyed NATO and Fulbright Postdoctoral Fellowships at the Niels Bohr Institute, and after that a postdoctoral fellowship in the Physics Division at Los Alamos National Laboratory. He began his academic career at Carnegie Mellon University in 1968, where he remained until 1991. There he built one of the country’s strongest university groups in medium energy nuclear physics. In so doing, he nurtured the careers of many students, post-doctoral fellows and young faculty.

Throughout the 1970’s and 80’s the Carnegie Mellon group was a leading participant in a broad scope of collaborative experimental research in a number of important emerging areas. At the Los Alamos Meson Physics Facility (LAMPF), the group was prominent in pion elastic and inelastic scattering experiments and in pion absorption studies leading to the ejection of one or two nucleons.

At the Argonne ZGS and the Brookhaven AGS the Carnegie Mellon group was a leading participant in ‘exotic atom’ physics research involving kaons, antiprotons and sigma-minus mesons. These experiments led to precise measurements of particle masses and magnetic moments and for a time provided the most precise experimental confirmation of the CPT theorem. The group was also involved in studies of kaon elastic and inelastic scattering, kaon absorption and double strangeness exchange reactions, and measurements of hypernuclear lifetimes.

Throughout the 1980’s and 90’s, Peter was active in a number of strangeness production experiments at the CERN Low Energy Antiproton Ring (LEAR). During his last twenty years he branched out further to work on a search for a neutron electric dipole moment and on heavy ion physics with the NA36 and PHENIX teams.

In 1991, Peter was named Director of the Los Alamos Meson Physics Facility and Director of MP Division, positions he held until 1993. At that time the facility shifted its focus to neutron physics and became a component of Defense Programs in the Department of Energy. From 1993 until 2000, he served as Director of the Physics Division at Los Alamos. In all of his leadership positions, Peter was greatly appreciated for his thoughtful, creative and strategic insight, his careful attention to detail while not losing sight of the “big picture,” and his genuine willingness to listen and to consult with colleagues. He handled scientific, personnel and budgetary matters firmly, fairly and deftly. Because of his exceptional judgment and strategic insight, he often served on physics panels and studies at the request of DOE and NSF. Perhaps most notable of these was his work as chair of the 1984 DOE panel on future electron scattering facilities for nuclear physics. Peter was also a fellow of the American Association for the Advancement of Science and the American Physical Society.

Peter greatly enjoyed the many opportunities he had to travel and to speak with people from all walks of life about how they lived and viewed the world. On a trip to Soviet Georgia a few years before the end of the Soviet Union, he was struck by the impassioned comments he heard from taxi drivers and shopkeepers, who, on learning he was from the U.S., said to him, ‘We want clear skies,’ meaning free of missile contrails. This experience spurred his interest and activity in international scientific relations as a means to promote understanding and peace among nations.

Peter is survived by his wife of nearly 50 years, Angela L. Barnes, their children Alexa B. Epstein, Peter D. Barnes, Jr., and Diana B. Philpott, nine grandchildren and his brother Frederick L. Barnes. Peter was the son of Arthur H. Barnes, a physicist prominent in the field of nuclear energy.

Peter leaves a legacy of great accomplishment in science as well as strong memories of his generosity, openness and sensitivity. He is greatly missed by family and friends the world over.