The Stefan Meyer Institute (SMI) is devoted to basic research in the field of subatomic physics. Our research focuses on the study of fundamental symmetries and interactions, addressing the following questions:
- What are the properties of the forces that exist in nature?
- What is the origin of the masses of the visible universe?
- Why do the remains of the Big Bang consist only of matter and not also of antimatter?
We specialize in precision spectroscopy of exotic atoms1 and exotic meson-nucleus bound states as an integral part of international collaborations at large-scale research facilities including
- CERN (Geneva, Switzerland),
- LNF-INFN (Frascati, Italy),
- J-PARC (Tokai, Japan),
- GSI (Darmstadt, Germany),
and, in the future,
- FAIR (Darmstadt, Germany).
These are among the world’s leading facilities for subatomic physics and our projects are subject to rigorous annual evaluation to monitor their progress in a dynamic and expanding field.
We aspire to perform research that increases the understanding of fundamental physics principles while simultaneously providing opportunities for young Austrians to obtain valuable experience at institutes unavailable to them at home.
The current two main fields of focus at SMI are:
- Study of the strong interaction and its corresponding theory, quantum chromodynamics (QCD), at low energies in the non-perturbative regime and at intermediate energies. Chiral symmetry and its breaking or restoration plays an important role. They contribute to the origin of the masses of hadrons. The sum of the masses of the three quarks adds up to only a few percent of the measured hadron mass, which originates mainly from the dynamic interaction between the quarks and the ex-change particles of the strong interaction, the gluons. The underlying mechanism is, to date, not un-derstood at all. The experimental approach is the spectroscopy of meson-nucleus bound states using large 4p detectors like FOPI and PANDA, and to measure the effect of the strong interaction on the low-lying atomic states of simple exotic atoms by X-ray spectroscopy.
- Matter-antimatter symmetry, especially the study of the underlying CPT symmetry. This symmetry is a property of all field theories used hitherto to describe nature, but is in contrast to the observed matter dominance of the visible universe. Furthermore, not all mathematical prerequisites of the CPT theorem are valid in modern theories like string theory or quantum gravity. Experimentally the matter-antimatter symmetry is investigated by precision measurements of properties of the antiproton (mass, charge, magnetic moment) in antiprotonic atoms and antihydrogen, comparing them to known properties of the proton.
Further activities include an underground laboratory experiment at Laboratori Nazionali di Gran Sasso (Italy) on a high-sensitivity test of the Pauli principle, in the VIP (Violation of the Pauli Principle) experiment.
Prof. E. Widmann
1 Atoms that contain another particle (e.g. an antiproton, kaon, muon or pion) in their shell instead of an electron.