Ludwig Tauscher (1939-2008)

Dear Colleagues,

It is with deep sorrow and regret that we inform you that our colleague and friend Ludwig Tauscher passed away on Sunday 23 November after a heart attack.

Ludwig studied physics at the University of Heidelberg, where he obtained his PhD in 1966. After several postdoctoral appointments at the MPI Heidelberg, and the Universities of Konstanz and Karlsruhe, he joined the University of Basel, where he became Professor of Physics in 1985.

Ludwig devoted his entire professional life to teaching and experimental physics. He arrived at CERN in the early seventies, where he performed several experiments at the SC and at the PS, studying exotic atoms with various probes such as μ-, π-, K-, and Σ-. In the early eighties he searched for the production of nucleon-antinucleon bound states at the PS, a subject that was the main motivation for the construction of the LEAR storage ring. At LEAR he studied neutral meson production and spectroscopy with the PS182 experiment, for which he was also the spokesman.

Ludwig was among the founders of the CPLEAR experiment (PS195), to which he made a very strong contribution from the time of the initial proposal in 1985 until the last publications in 2003. As head of the Basel group and organizer of the Swiss Universities effort, he participated in the trigger and the electromagnetic calorimeter construction and also helped to finalize much of the analysis on fundamental symmetries (CP, T and CPT) published by the CPLEAR experiment.

In 1994 Ludwig brought the Basel Institute into CMS. He was particularly involved in the Swiss activities of the CMS Pixel Detector. With his team he participated from the very beginning of the project in the design and construction of vital parts of the pixel detector as we know it today. Under his supervision several doctoral theses and diplomas were written, dealing with the issues of partial depletion of heavily irradiated silicon pixel sensors. For many years, he also represented Switzerland in the CMS Management and Collaboration Boards.

Between 1988 and 1996 he led the Forum of Swiss High Energy Physicists (the predecessor of the current Swiss Institute of Particle Physics, CHIPP) under the auspices of the "3eme Cycle de la Physique en Suisse Romande".

In parallel, his interest in LEP physics led him to join the L3 experiment. With contributions in all aspects of the activity, Ludwig managed to make the Basel group an indispensible member of the collaboration. He led his group to make important contributions in all aspects of scientific research. His ideas were implemented as a first level trigger in L3, which led to a considerable increase in the acceptance of the experiment. Later he focused on two-photon physics on which several of his students wrote their doctoral theses.

From the late nineties until his untimely death he was involved in the current DIRAC experiment (PS212) studying ππ-atoms. He was the project leader in the design and implementation of a high level trigger. Throughout the experiment, he was a leading scientist making essential contributions to the data analysis and interpretation of physics results. He enthusiastically supported the project for an upgraded setup for the improved measurement of the lifetime of ππ-atoms and the observation and future lifetime measurement of πK-atoms. As an outstanding and benevolent manager of this experiment he always strived to provide support and assistance to all members of the DIRAC collaboration.

After his retirement in 2004 he continued with his commitment to particle physics and related fields. Since 2005 Ludwig was an academic guest of the Laboratory for High Energy Physics (ETH Zurich) following the ongoing CMS activities. He also continued his duty as a distinguished member of the PSI Particle Physics Advisory Committee that he had fulfilled over many years.

The Swiss Particle Physics community has lost a highly distinguished and dedicated physicist, researcher and teacher who committed himself wholeheartedly to the education of young physicists. His warm and open character will be missed by all of us.

We convey our deepest condolences and sympathy to his family.

His friends and colleagues