Particle accelerators enable experiments in fundamental research and practical applications under conditions that would otherwise be unattainable. At the Helmholtz Institute Mainz (HIM) on our campus, for example, a compact accelerator is opening up new possibilities for improved radiation therapy. Advances in superconducting technology also allow us to carry out groundbreaking experiments in fundamental physics which were previously impossible due to technical or economic limitations. The new energy-recovering electron accelerator MESA, which is currently under construction at the Institute for Nuclear Physics, will begin operations in the near future. Additionally, the HELIAC heavy-ion accelerator, developed by a Mainz-based accelerator group, will be installed on the nearby GSI campus. This offers the exciting potential to produce nuclei of previously unknown chemical elements.

At the intersection of particle physics, stellar physics, and cosmology, the field of astroparticle physics aims to simultaneously further our understanding of the universe at large and the elemental particles it is composed of and provide us with more information about dark matter. To understand the often faint signals, we are involved in some of the most daring experiments in exotic places spread all around the globe. We study the most extreme conditions that appear in the universe through theoretical research and as members of international experimental collaborations. The detector laboratory and the new Center for Fundamental Physics enable us to develop new technologies to expand the boundaries of knowledge.

The Institute of Atmospheric Physics investigates how weather and climate develop and change. In six working groups—Theoretical Meteorology, Theoretical Cloud Physics, Earth System and Climate Modeling, Modeling of Cloud-Aerosol Dynamics Interactions, Aircraft Measurements and UTLS Transport Processes, and Atmospheric Trace Substances—we analyze the processes that shape weather events and climate and environmental change. By combining numerical models, experimental methods, and measurements in the atmosphere, we make an important contribution to a better understanding of atmospheric research and the Earth system as a whole.

In the atomic and quantum physics research groups at JGU Mainz, we investigate fundamental phenomena of the quantum world in individual atoms, ions, and photons. Using state-of-the-art techniques such as precision measurements, high-resolution laser spectroscopy, and quantum optics, we test fundamental symmetries, determine natural constants with the highest accuracy, and develop novel concepts for quantum information and quantum sensor technology. Our work combines cutting-edge experimental research with theoretical models to deepen our understanding of the fundamentals of physics and open up new technological applications.

The strong force binds quarks to hadrons and nuclei. We study what bound states exist and what their properties are. To this end, we conduct experiments using the electron accelerators MAMI and MESA on our campus and at IHEP Beijing, KEK in Japan, and CERN and PSI in Switzerland. These experiments are complemented by a strong theoretical effort using both lattice computations and analytical methods.

The goal of high energy particle physics is to deepen our understanding of the fundamental building blocks of nature, the elementary particles and their interactions, and to find out what is beyond the Standard Model of particle physics. Through theoretical research and our participation in large experimental collaborations involving some of the biggest machines mankind has ever built, we develop effective field theories and perform precision tests of the Standard Model, explore the physics of the Higgs sector, search for new physics and dark sectors, and investigate the secrets of quark and lepton flavors.

Mathematical physics uses mathematical methods to address problems in physics, aiming to rigorously define and systematically study the behavior of physical systems. As modern mathematics inspires research in physics and vice versa, mathematical physics is an interdisciplinary research field that bridges theoretical physics and pure mathematics.

In Mainz, research in mathematical physics focuses predominantly on questions in theoretical high energy physics, with an emphasis on perturbative and non-perturbative treatments of quantum field theories as well as on string theory, offering a framework for quantum gravity.

The interplay of many quantum mechanical degrees of freedom in solid-state systems gives rise to entirely new states of matter. These emergent phases – often engineered in precisely tailored materials – can exhibit non-trivial topologies with remarkable electronic, optical, and magnetic properties. Research in quantum matter and spintronics combines fundamental science with cutting-edge technologies, paving the way for energy-efficient memory, advanced sensing, and revolutionary approaches in artificial intelligence.

Wherever there is life, there is soft matter. These materials – based on colloids, (bio)polymers, surfactants, foams, gels, and similar systems – exist between the conventional phases of matter, being neither true liquids nor true solids. Governed by an interplay of multiple weak molecular interactions, mesoscopic organization, and emergent behavior, they are easily deformed by thermal fluctuations and have strong and efficient responses to external stimuli. Soft matter physics lies at the heart of the mechanics of life and the design of next-generation functional systems.