Yoshio Yamaguchi

Abstract

Yoshio Yamaguchi, an icon of postwar Japanese high-energy physics and a strong advocate of international collaboration, died of pneumonia on 12 August 2016 in Tokyo. Yoshio Yamaguchi AKIKO YAMAGUCHI, 2010PPT|High resolutionBorn on 29 January 1926 in Takefu, Japan, Yamaguchi received his bachelor’s degree in physics in 1947 and a doctor of science degree in physics in 1953 from the University of Tokyo. His dissertation was entitled “Phenomenological analysis of meson processes.”In 1949 Yamaguchi joined Osaka City University as a cofounder of its particle-physics theory group. His proposal that the newly discovered particles in cosmic-ray collisions are created in pairs led to the eventual understanding of strange particles. Yamaguchi started his international career in 1953 at the University of Illinois at Urbana-Champaign; during his two years there, he proposed a separable nuclear potential.In 1957 Yamaguchi was invited to the theory division at CERN. At the time, CERN was in its infancy, and the newly created theory division was attracting numerous superb physicists, with whom Yamaguchi had deep and fruitful interactions and developed close, lasting friendships. His experience during that period greatly influenced Yamaguchi’s passion for international collaboration throughout the rest of his life.Yamaguchi played a vital role in evaluating and consulting on experimental programs at CERN. According to local legend, anyone seeking to get a new research experiment approved first had to convince him to support it. His four years at the organization convinced him that experimental study and verification by means of accelerators were crucial to advancing high-energy physics. While at CERN, he also laid the groundwork for a theory on SU(3) and other flavor symmetries in particle physics.After leaving CERN, Yamaguchi went to the Institute for Nuclear Study (INS) at the University of Tokyo as head of the theory group. In 1968 he moved to the university’s physics department, where he taught and supervised many students. He was not only an excellent researcher but also a dedicated educator. His enthusiasm for and deep knowledge of high-energy physics inspired many young scientists. As one of his students, I witnessed lively discussions every week during and after his High Energy Physics lectures, which attracted many students and staff members.Yamaguchi strongly believed that significant progress can be achieved only if experimental and theoretical physics researchers work hand in hand. He made great efforts to establish experimental high-energy physics by introducing high-energy proton accelerators in Japan. He was instrumental in the creation of the National Laboratory for High Energy Physics and of KEK, the High Energy Accelerator Research Organization.An excellent manager, Yamaguchi returned to the INS as director in 1983 until his retirement in 1986. He was a cofounder and chair of the International Committee for Future Accelerators, which promoted a worldwide network of collaborations. As a member of the Scientific Policy Committee at CERN, he was responsible for, among other things, further promoting international collaborations. He served as president of the Physical Society of Japan in 1986–87. In 1993 he became the first person from Japan to be elected president of the International Union of Pure and Applied Physics. Yamaguchi contributed a great deal to the creation of the Association of Asia Pacific Physical Societies and the Asia Pacific Center for Theoretical Physics.Yamaguchi had a tasteful knowledge of the culture of Japan and the world, especially of the classical period. He often impressed colleagues with his memory of his many intellectual conversations with them. His talks were full of wit and humor, which was somewhat exceptional for a Japanese person. Some years ago his friends and students had a chance to listen to his stories about physics and physicists from the early days of postwar Japan; the stories were so vivid that they left a lasting impression. Many of us pray sincerely that Yamaguchi’s hope and enthusiasm for international collaboration and high-energy physics will inspire the coming generation of researchers in Japan and around the world.© 2017 American Institute of Physics.