PARTICLE PHYSICS

DESY mourns the loss of Max Klein, who passed away on 23 August 2024. The particle pyhsicist worked at DESY for many years, in particular on the H1 experiment, and later, as a professor in Liverpool, headed the ATLAS experiment working group there.

Max Klein studied at the Humboldt University in Berlin and received his PhD there in 1976. From 1973 to 1991, he was employed as a scientist at the Institute for High Energy Physics (IFH) in Zeuthen, today´s DESY site there. During this time, he spent research periods at the JINR research centre in Dubna, at DESY in Hamburg and at CERN. Max Klein became a DESY employee after the fall of the Berlin Wall in 1992. He worked from Hamburg and Zeuthen in the H1 collaboration at the HERA accelerator and, together with his working group, made decisive contributions to understanding the structure of the proton and, in particular, to determining the gluon density in the proton. From 2002 to 2006, he was spokesperson of the international H1 team of around 350 people.

In 2006, Max Klein accepted an appointment at the University of Liverpool and joined the ATLAS collaboration at the LHC accelerator with his working group in 2007. He led the Liverpool ATLAS group until 2017.

Throughout his career, Max has been a strong advocate of a next-generation electron-proton accelerator. For this successor to HERA, he wanted to add an electron accelerator to the LHC, creating an LHeC (Large Hadron electron Collider). To this end, he worked closely with the CERN accelerator group and other international teams on research and development.

Max Klein received many honours during his career, including the Max von Laue Medal from the GDR Academy of Sciences in 1985. In 2013, he was awarded the Max Born Prize for his fundamental contributions to understanding the structure of the proton.

“Max Klein was a passionate, extremely accomplished and reflective physicist who had a huge impact on both DESY and particle physics as a whole,” says Beate Heinemann, Director of Particle Physics at DESY. “With his untimely death, we have lost a truly special person who, with his enormous knowledge, courage, humour, patience, tolerance and kindness, was a role model and mentor for an entire generation of physicists.”