EXC 2118:  Precision Physics, Fundamental Interactions and Structure of Matter (PRISMA+)

• Subject Area: Particles, Nuclei and Fields ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: since 2019
• Website: Homepage
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 390831469

The Standard Model of particle physics describes nature at its most fundamental level, from the interactions of elementary particles to the structure of hadrons and nuclei. Despite its success, it fails to explain several phenomena, such as the existence of dark matter and the abundance of matter over antimatter. Several puzzles in low-energy precision experiments challenge the validity of the Standard Model and might provide first hints at fundamentally new physics. PRISMA+ is focused on a comprehensive investigation of these deep open questions. We will search for new particles and new forces using a combination of innovative precision experiments performed on campus and leading contributions to large-scale international experiments. The Mainz Energy-recovering Superconducting Accelerator (MESA) forms the basis for several flagship experiments including the world's most precise measurement of the weak mixing angle and new searches for light dark sector particles in previously unexplored territory. The proton radius puzzle will be addressed via the combination of precision spectroscopy on trapped atoms and electron-proton scattering at MESA. A refined measurement of the neutron lifetime at the TRIGA reactor will help to resolve a discrepancy in existing measurements of this important quantity. The tension between measured and predicted values of the anomalous magnetic moment of the muon will be scrutinized using novel theoretical computations and more precise measurements of hadronic input quantities. \pp will also focus on the physics of neutrinos and other weakly interacting particles, including dark matter candidates. The neutrino mass ordering and absolute mass scale will be addressed by the JUNO and Project8 experiments with leading contributions from \pp researchers. Our new involvement in long-baseline neutrino physics is focused on detecting CP violation in the lepton sector. WIMP dark matter will be searched for with the XENONnT direct detection experiment, complemented by searches for very light dark matter particles with the Mainz-based GNOME and CASPEr precision magnetometry experiments. The Standard Model will be confronted with the world's best measurement of the W-boson mass and determinations of Higgs couplings at ATLAS. The broad experimental effort is supported by theoretical precision calculations, model building and the development of search strategies for new physics. The Mainz Institute for Theoretical Physics boosts these activities by hosting workshops and bringing renowned international experts to Mainz. MESA and the Detector Laboratory form the basis for an extensive program in accelerator science and hardware developments, as well as a unique training environment. The Mainz Physics Academy will create an umbrella structure for measures in education, training, recruiting and early-career support. PRISMA+ will promote equal opportunities by significantly expanding the established Irène Joliot-Curie Program.

• DFG Programme: Clusters of Excellence (ExStra)
• Applicant Institution: Johannes Gutenberg-Universität Mainz
• Participating Institution: GSI Helmholtzzentrum für Schwerionenforschung GmbH; Helmholtz-Institut Mainz
• Spokespersons: Professor Dr. Matthias Neubert; Professor Dr. Hartmut Wittig
• Participating Researchers: Professor Dr. Kurt Aulenbacher; Professorin Dr. Sonia Bacca; Professor Dr. Niklaus Berger; Professor Dmitry Budker, Ph.D.; Professor Dr. Sebastian Böser; Professor Dr. Volker Büscher; Professor Dr. Achim Denig; Professor Dr. Christoph Düllmann; Professor Dr. Wolfgang Gradl; Professor Dr. Werner Heil; Professorin Dr. Gabriele Monika Honecker; Professor Dr. Joachim Kopp; Professor Dr. Frank Maas; Professorin Dr. Lucia Masetti; Professor Harvey Byron Meyer, Ph.D.; Professor Dr. Uwe Oberlack; Professor Dr. Randolf Pohl; Professor Dr. Matthias Schott; Professor Dr. Pedro Schwaller; Professorin Dr. Concettina Sfienti; Professor Dr. Marc Vanderhaeghen; Professor Dr. Stefan Weinzierl; Professor Dr. Michael Wurm