Research Area A: Fundamental Interactions

Research Programme

Symmetries and conservation laws determine the interactions between particles and the structures in which matter organizes itself. High precision tests of fundamental interactions and of symmetry breaking are performed on all energy and length scales – from ultra-cold neutrons to the highest energies accessible in particle and astroparticle physics.

One of the major research goals is the measurement of the weak mixing angle with world-record accuracy at low and high energies using the MESA facility as well as the LHC.Searches for a new light gauge boson, which could explain the anomalous magnetic moment of the muon and act as a messenger to the dark-matter sector, will be performed at MAMI and at MESA. Important questions in flavour physics are addressed by studying the flavour-changing couplings of quarks and neutrinos with high precision, using a wide variety of experimental approaches.Tests of fundamental symmetries such as Lorentz, CP and CPT invariance are performed using atom and ion traps as well as meson decays.

PRISMA provides new opportunities through the construction of the high-intensity MESA accelerator, which will enable a new class of high-precision electron-scattering experiments. In addition, PRISMA strengthens the research in the area of low-energy precision experiments by upgrading the TRIGA research facility to provide one of the world’s strongest pulsed source of ultra-cold neutrons.

The TRIGA reactor in Mainz has one of the strongest sources of ultra-cold-neutrons (UCN) in the world. The central experiment at this UCN-source is the τSPECT experiment to measure the lifetime of the neutron. The neutron lifetime is used for precision tests of the standard model (determination of the Vud-element of the CKM quark mixing matrix) and it is one of the crucial parameters during big bang nucleosynthesis since it determines the abundance ratio of the light elements. Presently the τSPECT experiment is being set-up at TRIGA. A first measurement will be performed in summer 2015.