by The ALICE Collaboration. Published: 14 March 2017

Helmut Oeschler [Image credit: J Stroth]

Helmut Oeschler, an active member of the ALICE collaboration, passed away from heart failure on 3 January while working at his desk. Born in Southern Germany, he received his PhD from the University of Heidelberg in 1972 and held postdoc positions at the Niels Bohr Institute in Copenhagen, and in Strasbourg, Saclay and Orsay in France. From 1981 he was at the Institute for Nuclear Physics of TU Darmstadt. He held a Doctorate Honoris Causa from Dubna University, Russia, and in 2006 he received the Gay-Lussac-Humboldt prize.

Oeschler’s physics interests concerned the dynamics of nuclear reactions over a broad energy range, from the Coulomb barrier to ultra-relativistic collisions. He was a driving force for building the kaon spectrometer at the GSI in Darmstadt, which made it possible to measure strange particles in collisions of heavy nuclei. From the late 1990s he was actively involved in addressing new aspects of equilibration in relativistic nuclear reactions.

Oeschler became a member of the ALICE collaboration at CERN in 2000 and made important contributions to the construction of the experiment. Together with his students, he was involved in developing track reconstruction software for measuring the production of charged particles in lead–lead collisions at the LHC. He also led the analysis efforts for the measurements of identified charged hadrons in the LHC’s first proton–proton collisions. From 2010 to 2014 he led the ALICE editorial board, overseeing the publication of key results relating to quark-gluon matter at the highest energy densities. His deep involvement in the data analysis and interpretation continued unabated and he made important contributions to several research topics. Advising and working in close collaboration with students was a much loved component of Helmut’s activity and was highly appreciated among the ALICE collaboration.

Helmut Oeschler was a frequent visitor of South Africa and served there on numerous international advisory committees. He was instrumental in helping the South African community develop the physics of heavy-ion collisions and collaboration with CERN.

With Helmut Oeschler we have lost an internationally renowned scientist and particular friend and colleague. His scientific contributions, especially on the production of strange particles in high-energy collisions, are important achievements.

[This text appeared on the CERN Courier, issue March 2017]

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We will remember Helmut Oeschler as one among the most active members of the ALICE Collaboration. On one hand, he was enthusiastically involved in several aspects of our physics programme with a particularly strong and clear focus on soft physics. On the other hand, he committed himself to the management of the Collaboration by chairing during four years the ALICE editorial board. Hence he was instrumental in the high quality of the ALICE papers and in organizing timely their publication.

Not only was he an exceptionally praised colleague, but for many of us he was above all a true and great friend. He was always available for enlightening discussions whether they were on the latest scientific results or on the respective quality of French or German wines. Arguing with him was fun and constructive thanks to his in-depth knowledge of physics (and many other subjects as well) and, when coming to criticism, he used to do so as a true gentleman.

We all remember him shooting pictures at every occasion when the Collaboration met, which allowed him to build a rich catalogue of faces and attitudes we would all be eager to browse. He was a very good amateur photographer, indeed, as he also proved with his astonishing photo-reportage of the wild life at Kruger Park in South Africa.

For several of us he was a mentor: he directed the research work of many students, giving them wise advice at every stage of their academic career, motivating them during tough times when problems became more complicated than expected or when results did not arrive promptly enough.

He was enthusiastic, cultivated and cheerful: he deeply enjoyed collaborating, creating links between people, even between strong opponents, helping them to interact in a gentle and colourful manner.

We will miss his presence and, despite our profound sadness, we will always remember both his contagious laughter and his amazingly honest smile. 

• His friends and colleagues.