Research: Elementary Particle and Astroparticle Physics


We are investigating fundamental properties of matter particles and their interactions at the highest energies. With the CMS experiment at CERN in Geneva we are working at the highest laboratory center-of-mass energies (introduction in German), and with the Pierre-Auger Observatory in Malargüe/Argentina we exploit the highest energy particles of the universe (introduction in German).



With the CMS experiment at CERN our primary research topic is search for new physics phenomena in association with top quarks. Top quarks are the heaviest elementary particles observed so far. We have published with CMS cross section measurements of electroweak top quark production, and searches for new heavy resonances decaying to top quark pairs. We have also published searches for contact interactions using di-jet final states.

Currently we are working on a measurement of the fundamental coupling of top quarks and the Higgs boson. The Higgs has been observed by the CMS and ATLAS experiments recently.

With the Pierre-Auger-Observatory in Argentina our research topic is the physics of ultra-high energy cosmic rays. Within the project CRPropa 3 we developed a 3D program to propagate millions of cosmic rays from their sources to observation. We conclude on the origin, composition, and propagation of the cosmic rays by comparisons of the simulation results with data measurements. We have published the simulation program, and new methods for concluding on cosmic magnetic fields the cosmic rays traverse.

We also develop new technology for detecting air showers initiated by ultra-high energy cosmic rays using broadband MHz antennas. We have published with the Pierre-Auger experiment a thorough comparison of different antenna types. Recently we deployed 124 new antenna stations in Argentina, and are working on analyzing the measurements to obtain new and additional information on the primary cosmic ray.

In our third research area we contribute to the GRID computing technology of the CMS experiment. Beyond this, we provide development environments for physics analyses based on graphical components. With the project VISPA (Visual Physics Analysis) we support physicists in the analysis development cycle including the analysis design, execution, and verification of the results. The VISPA environment is used both in science and education. In the past decade, the continuously advancing project lead to many conference contributions.

A new version of the VISPA internet platform has been developed, enabling physicists and students all over the world to program algorithms, and to perform physics data analysis using their web browser.