The Standard Model of particle physics enables precise predictions for several of its observables. For instance, by knowing the mass of the Z boson, the top quark, and the Higgs boson, as well as the electroweak mixing angle and the fine structure constant, one can predict the mass of the W boson. If significant disparities arise between the predicted and measured values of the W boson mass, it would suggest an issue with the Standard Model—essentially indicating the observation of indirect effects stemming from unknown (new) physics.

While we all believe that Quantum Chromodynamics is the correct theory for describing the strong force, reliable predictions can only be made for high-energy processes where the strong coupling constant is small. Nevertheless, there exists a rich phenomenology of low-energy QCD processes that could provide valuable insights into describing the strong force in close proximity to confinement. We investigate these non-perturbative QCD effects at the ATLAS Experiment, utilizing both proton-proton and heavy ion collisions.

While axions were initially proposed to offer an elegant solution to the strong CP problem, it has become apparent that a broader category of light and weakly interacting particles is theoretically well motivated. These axion-like particles exhibit a diverse range of phenomena but always couple to photons. This forms the foundation of our search endeavors. In recent years, it has been revealed that searches for axion-like particles can be repurposed to investigate high-frequency gravitational waves. We have recently initiated such efforts in Mainz and Bonn.

A huge detector as ATLAS requires many people who keep it running and prepare it for the next years. Our group is responsible for the data quality of the muon spectrometer as well as contributing to the upgrade of the muon detector and its trigger system. This involves numerous software, hardware and detector developments starting direct hardware coding over FPGAs to fast data-transmissions. Since 2024, we also took over the responsibility for the maintenance of the Detector Control System (DCS) of the new ATLAS NSW systems.

As every good experimental group, we are also developing new detector technologies. We are focussing on micropattern gaseous detectors, in particular on the Micromegas technology. This was the basis for several of our new detector designs, such as the first prototype of the ATLAS Muon System Upgrade, but also preshower detectors and double-sided readout designs. Luckily we can test our prototype detectors not only with X-rays and cosmic rays, but also at test-beam facilities at MAMI in Mainz and ELSA in Bonn. 

Machine learning techniques have become increasingly popular in the context of particle physics. Our group is actively developing new object and event classifiers using deep neural networks. Additionally, we are exploring the potential of transfer learning and adversarial attacks.

During the Covid-19 pandemic, we began adapting an agent-based simulation framework originally designed in the UK for application in Germany. We also incorporated vaccinations and various virus types into the simulation. In this context, we examined the impact of school closures and investigated the role of statistical uncertainties in influencing infection rates at a local level.