Research Descriptions
Short-range Gravity Experiment
Below find pictures and publications from an experiment, installed at the Indiana University Cyclotron Facility, designed to test the Newtonian inverse square law (ISL) at distance ranges less than 100 microns. This experiment, originally installed at the University of Colorado, uses a high-frequency technique departing from the traditional torsion-pendulum approach. Planar, 1 kHz tungsten oscillators are used as test masses with a stiff conducting shield in between them to suppress backgrounds. The 1 kHz operational frequency is chosen since at this frequency it is possible to construct a simple passive vibration isolation system, consisting of a stack of massive disks suspended by fine wires. Modifications to the ISL at short range, arising from new elementary particles or even extra spacetime dimensions, are predicted from many models that attempt to describe gravity and the other fundamental interactions in the same theoretical framework.
Pictures
Experimental test masses and shield
Central apparatus with vibration isolators
Photos
Close-up of experimental test masses and shield
Central apparatus with vibration isolators
Results and projected sensitivity
Refereed publications
Nature 421 (2003) 922: The principal publication of the first experimental results
C.R. Physique 4 (2003) 337: Review article with short description of apparatus and results from this and other short-range gravity experiments
Nucl. Phys. B 539 (1999) 23: Description of original proposal and sensitivity calculation
Rev. Sci. Instrum. 70 (1999) 2742: Technical description of the vibration isolation system
Conference proceedings
Search for Lorentz Violation in a High-Frequency Gravitational Experiment Below 50 Microns, in Fourth Meeting on Lorentz and CPT Violation (World Scientific, 2008) 475: Update on the experiment installed at Indiana and search for Lorentz violation signals in 2002 data
Tests of Gravity at the 100 Micron Scale and Below, in Proceedings of the SLAC Summer Institute on Particle Physics (SSI05), Menlo Park, CA, 2005: Review article with descriptions of apparatus, results, and proposals for Indiana experiment and others in the distance regime from nanometers to millimeters
Gravitational Experiment Below 1 Millimeter and Comment on Shielded Casimir Backgrounds for Experiments in the Micron Regime, (preprint), in: Proceedings of the Ninth Marcel Grossmann Meeting on General Relativity (World Scientific, 2002) part C, 1819-1825: Early progress report on Colorado experiment and calculation in support of proposal for shielding Casimir-type forces in nanometer range experiments
Arxiv preprints
arXiv:hep-ph/0210004v3: Complete description of apparatus and analysis in support of principal publication of first experimental results (see above)
