Berlin 2005 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

SYRN: From quantisation in the gravitational field to correlated electron systems - Perspectives of research with neutrons

SYRN 1: Perspectives of research with neutrons

SYRN 1.7: Invited Talk

Tuesday, March 8, 2005, 17:30–18:00, TU HE101

Gravity at a Micron and Mixing of Quarks - Particle Physics with Cold Neutrons — •Hartmut Abele — Physikalisches Institut, Philosophenweg 12, 69120 Heidelberg

Galilei Galileo would be somewhat surprised. According to his famous free-fall experiment, all objects fall independent from its mass with constant acceleration g. But neutrons do not fall as larger objects do. When neutrons become ultra-cold, the fall experiment shows quantum aspects of the subtle gravity force in the sense that they don’t fall continuously. We find them in bound quantum states with discrete energy levels of pico-eV, opening the way to a new technique for gravity experiments and measurements of fundamental properties. New motivations for gravity experiments come from frameworks where the Planck scale is taken to the energy scale of the Standard Model, the theory of particle physics. Considering the very early stage of our universe, we have the strong feeling, that a Standard Model description is incomplete, and many new observables pointing to physics beyond the Standard Model emerge from superstring theory, supersymmetry or other Grand Unified Theories. Furthermore, the quark-mixing (CKM) matrix remains unexplained in the Standard Model as well as CP-violation, which might explain the baryon-antibaryon asymmetry of the universe. Some observables of these theories require neutron physics, for others the neutron provides one of several possible ingredients.

These examples show that questions of particle physics and cosmology at highest energies can be pursued at the other extreme of the energy scale, using neutrons at the lowest energies down to the pico-eV range.