The centerpiece of experimental investigations in nuclear and particle physics is the Mainz Microtron MAMI, an electron accelerator for energies up to 1.6 GeV. MAMI’s excellent beam quality enables high-precision scattering experiments focused on gaining insights into the details of the substructure of hadrons consisting of quarks and gluons – and thus making important contributions to our understanding of the internal connections of our universe. The exciting search for exotic particles, such as dark photons, is also part of the physics program.

The novel accelerator MESA (Mainz Energy-recovering Superconducting Accelerator) is currently being developed and built specifically for precision tests of the Standard Model in the low-energy range. The innovative energy recovery design ensures the energy-efficient acceleration of electrons, so the highest possible beam intensities are available for research. The planned experiments aim to measure various fundamental quantities such as the proton radius or the mixing angle of electroweak unification with previously unattainable precision at lower energies. Such quantities play an important role in exploring to what extent the established theory of elementary particles is valid.

The TRIGA Mark II research reactor is one of only two research reactors in Germany and is used intensively for basic and applied research in the fields of nuclear chemistry, nuclear physics, neutron physics, chemical analysis, and in medical research. Two sources for so-called ultracold neutrons are currently operated at TRIGA Mainz for high-precision measurements of the free neutron. This makes JGU one of the few institutions worldwide where such measurements are possible.

The PRISMA Detector Lab promotes cooperation and the exchange of experience and technology within the Cluster of Excellence PRISMA⁺: Laboratories and workplaces are available to scientists with different hardware expertise and offer everyone a common research environment and infrastructure. As part of this cooperation, the detector lab provides access to its own special laboratories, high-quality equipment, and design software. The electron and photon beams at MAMI and the irradiation facility at the TRIGA reactor are also available for the testing and characterization of detectors and electronics.

With the world’s only vertical wind tunnel, the scientists of the Aerosol and Cloud Physics group can bring a piece of cloud into the laboratory: Cloud and precipitation particles can be examined floating in a vertical air flow under almost atmospheric conditions. This permits the study of the physical and chemical properties of these particles as well as their role in the development of clouds, weather and climate.

In contrast to many other cloud physics laboratories, the Mainz wind tunnel allows the investigation of the properties and interaction of relatively large particles such as raindrops and hailstones. Such data are essential for the improvement of weather forecasting models and the interpretation of remote sensing.

The Center for Data Processing of Johannes Gutenberg University Mainz operates supercomputers, whose enormous computing capacities enable researchers to achieve ambitious goals in a wide variety of disciplines such as high-energy physics, meteorology, and the life sciences.

Along with the University of Kaiserslautern-Landau, the Goethe University Frankfurt, and Saarland University, JGU is part of the cross-state consortium of National High Performance Computing (NHR) South-West. The National High Performance Computing Alliance (NHR) provides computing capacities and strengthens methodological competence through the coordinated training and further education of users and young scientists. At the location in Mainz, the new HPC system MOGON NHR South-West has replaced MOGON I and MOGON II and expands the computing capacities of the cross-state consortium and is available to research groups from all over Germany.