Prof. em. Dr. Hans Jörg Leisi

Hans Jörg Leisi was elected assistant professor in 1970 and associate professor in 1973. He has been Professor Ordinarius of Physics at the ETH Zurich since 1981 and retired in April1998.

Prof. Leisi comes from Attiswil/BE and was born on 18 February 1931. He spent his high school years at Solothurn. Between 1950 and 1955, he studied physics at the ETH Zurich (ETH Zurich), completing his Ph.D. as an assistant in the Physics Department of ETH Zurich with Professor P. Scherrer. He was awarded the ETH medal for his Ph.D. dissertation on the topic of "Monoenergetic positrons". Between 1960 and 1965 he worked in the U.S., first as research associate at the University of Pennsylvania, Philadelphia PA (1960-1961), subsequently as postdoctoral fellow at the Bartol Research Foundation of the Franklin Institute, Swarthmore, PA (1961-1963) and finally as staff member at the Bartol Research Foundation of the Franklin Institute (1963-1965). Since 1965, he was employed at the Laboratory for High-Energy Physics, Institute for Medium-Energy Physics and Institute for Particle Physics where, in 1967, he completed his habilitation thesis entitled: "Interference Phenomena in Perturbed Angular Correlations".

The research activities of H.J. Leisi concentrated on low-energy particle physics, using mainly atomic physics methods to study the elementary interactions. In his research group, precision X-ray spectroscopy was developed as an efficient tool for particle physics. The group has measured the strong-interaction properties of the 1s ground state of pionic hydrogen. From this and other experiments, new and precise information on the symmetry structure of quantum chromodynamics (the fundamental theory of the strong interaction) was obtained.