- Director-General, European Organization for Nuclear Research (CERN), Switzerland
Most scientific work has focused on study of electron-positron reactions, the development of experimental techniques, and construction and operation of large detector systems. CERN: 1984-98, working for OPAL experiment, electron-positron storage ring LEP; since 2009, Director-General, CERN. 1998, Chair, University of Hamburg, established a working group to prepare experiments at an electron-positron Linear Collider that quickly became one of the leading groups in this field worldwide; 2004-08, Research Director, Particle and Astroparticle Physics, DESY laboratory. Member of many scientific committees and advisory bodies. Recipient of honorary Doctor of Science degrees in several universities in Europe and Canada.