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GR: Fachverband Gravitation und Relativitätstheorie
GR 302: Postersitzung
GR 302.1: Poster
Mittwoch, 7. März 2007, 16:15–19:00, Nordfoyer
Probing non-Newtonian gravity using Atomic Beam Spin Echo — •Felix Laux, Ulrich Warring, Ulrich Schmidt, and Maarten DeKieviet — Physikalisches Institut der Universität, Philosophenweg 12, 69129 Heidelberg
The inverse square law of gravity appears to be valid from cosmic scales down to the 0.2 mm range. However, this law might change outside this range in the light of developments in higher-dimensional field theory, and new experiments on gravitation are motivated by string theories with large volume compactifications and/or low string scale. Some of these theories predict modifications of Newtonian gravity in the submilimeter range due to repulsive forces mediated by possible abelian gauge fields in the bulk. The strength of the new force would be 106 to 1012 times stronger than gravity. Therefore, effects could be expected at sub-millimeter, even at atomic and nuclear length scales.
In this project a new approach is used to track these deviations from Newton’s law. We propose to improve the limits in the range between 1nm and 1µm by at least one order of magnitude through Casimir force experiments with cold atoms. It involves an Atomic Beam Spin Echo experiment, in which quantum reflection is used as a very sensitive tool for the exact shape of the atom-surface potential (i.e. for Yukawa contributions). By comparing the quantum reflectivity for 3He with that for 4He atoms many systematic errors (e.g. due to electromagnetic interaction) can be avoided and the experiment essentially probes the gravitational potential of one additional neutron at submicron distances.