Around EUR 180,000 for participation of the PRISMA+ Cluster of Excellence in the tSPECT and Mu3e experiments and the international NEMESIS and BEYOND consortia

Researchers at Johannes Gutenberg University Mainz (JGU) are involved in the major international research consortia NEMESIS (“Neutron Experiments join Muon Experiments for Synergy in Investigation and Search for new physics”) and BEYOND (“Search for physics beyond the Standard Model at the high intensity frontier, from new physics to spin-offs”), which address key issues in modern particle physics and bring together expertise from Europe, the USA, and Japan. Both consortia have now been selected for funding through the Marie Skłodowska-Curie Actions (MSCA). With this program, the European Commission funds research and innovation projects to promote the careers of outstanding researchers.

The JGU researchers involved in NEMESIS and BEYOND now have around 180,000 euros at their disposal to cover travel expenses for the preparation and implementation of the tSPECT, n2EDM and Mu3e experiments at the Paul Scherrer Institute (PSI) in Switzerland. tSPECT and Mu3e are core experiments of the recently approved PRISMA++ (Precision Physics, Fundamental Interactions and Structure of Matter) Cluster of Excellence, the follow-up project to the PRISMA+ Cluster of Excellence. Both experiments benefit greatly from the infrastructure of the “PRISMA Detector Laboratory” at JGU. However, they are being carried out at PSI, Switzerland's largest research institute with more than 2,300 employees, because its unique accelerator infrastructure provides, among other things, the necessary neutron and muon rates.

tSPECT: New methods for studying ultracold neutrons

The tSPECT experiment, which is being researched by Professor Martin Fertl's team at the JGU Institute of Physics, is investigating the lifetime of free neutrons. The aim is to clarify an existing discrepancy between different measurement methods and to establish a new technique for capturing so-called ultra-cold neutrons. In contrast to high-energy experiments, the particles in this experiment are not accelerated. Instead, the researchers slow down the particles so that they can be captured. Whether their properties match the predictions of the standard model of particle physics can thus be determined with high precision. This precision is achieved by generating and studying a very large number of neutrons. “Travel supported by NEMESIS enables my doctoral students and postdocs to learn and use experimental techniques directly at the Paul Scherrer Institute,” says Fertl. “In addition, the international networking of the members of my working group is strengthened by specific NEMESIS events.”

Mu3e: The search of a “forbidden” decay

The Mu3e experiment aims to discover a process that is “forbidden” according to the standard model of particle physics: the decay of a muon into three electrons or positrons. A clear observation of this decay would be a direct indication of “new physics”, beyond the standard model. The group led by Professor Niklaus Berger from the Institute of Nuclear Physics at JGU plays a key role in the development of the extremely fast detectors required for this. “The funding permits the researchers from Mainz to contribute directly to the commissioning and data acquisition phases of the Mu3e experiment at the Paul Scherrer Institute, allowing them to experience firsthand the results of many years of preparation,” says Berger.