Revolution in particle physics: Heidelberg researchers are chasing new decays!

Revolution in particle physics: Heidelberg researchers are chasing new decays!

Particle physics is facing an exciting phase, as the Mu3e experiment at the Paul Scherrer Institute is now being supported with a second funding period. Heidelberg physicists are significantly involved in this groundbreaking research project, which aims to gain deeper insights into the fundamental laws of physics.

A central goal of the Mu3e experiment is to investigate decays of antimuons into one electron and two positrons. Such a process is extremely unlikely in the Standard Model of particle physics because it changes the lepton number. However, according to current theories, including those from supersymmetry, this decay may occur more frequently than previously thought. The researchers intend to analyze more than 10^16 muon decays to collect valuable data about these rare events.

Technological advances

Heidelberg scientists have made groundbreaking progress in developing detector technologies that are essential to the Mu3e experiment. An ultra-thin silicon pixel detector was developed at the Physics Institute under the direction of Prof. Schöning, which records the decay particles with high precision. In addition, a highly developed detector for rapid time recording with a time resolution of less than 100 picoseconds was designed at the Kirchhoff Institute for Physics.

In order to ensure high sensitivity in the search for previously undetected decay, the latest technologies are used in the instrumentation of the particle detector. The detector has a spatial resolution of better than 200 μm, a temporal resolution of less than 100 ps and an energy resolution of better than 0.5 MeV for the individual electrons. This is made possible by the use of semiconductor detectors and scintillator fibers, which allow the decays to be measured precisely.

The Rolls results of the financing

With the approved funds, the Mu3e experiment can now be completed and the structure can be fully implemented. The first data from the experiment is expected in 2026, and full data collection should be enabled by 2028 at the latest. This means scientists will be able to detect decay or put an upper limit of 10^(-16) on the probability of decay, a 10,000-fold improvement compared to previous experiments.

In addition, the funding will also include funds for development work on a second expansion stage of the experiment, which is scheduled to begin around 2030. The Mu3e experiment has the potential to not only test existing theories of particle physics, but also to investigate new, light dark sector particles such as dark photons. By generating the world's most intense muon beam, an analysis of two billion decays per second will take place, which is of enormous importance for economic and fruitful research.

The ongoing research and development activity within the Mu3e experiment not only offers new perspectives for particle physics, but also a promising outlook for future science. Heidelberg physicist and international partners such as the University of Mainz, the Karlsruhe Institute of Technology and institutions from Great Britain and Switzerland play a crucial role. Mu3e is therefore followed with great interest by both the research community and the wider public.