Contact Information
Department of Physics525 Northwestern Avenue
West Lafayette, IN
47907-2036
Map and Directions
Telephone:
(765) 494-2970
Fax:
(765) 494-0706
Ricardo S. Decca - General Colloquium
January 22, 2004
Ricardo S. Decca
Department of Physics
Indiana University-Purdue University Indianapolis
Title: Searching for extra dimensions in the Casimir regime
The Colloquium will revolve around measurements of small forces at short separations in a Casimir-like geometry: How to get precise measurements of Casimir forces, and how to do a Casimir-less experiment. After briefly introducing the reasons behind Casimir measurements, I will present the experimental setup. Its heart resides in the use of a dynamical scheme to measure the attractive force between two metallic layers, one of them deposited on a high quality microelectromechanical torsional oscillator. The approach yields a sensitivity of about 6 fN/Hz1/2, which permits a direct comparison with theoretical models at an unprecedented level. Possible sources of discrepancies will be presented and discussed, as well as our efforts to control them. In the second part of the presentation, I will describe an approach that yields the best characterization for new weak forces at short separations. Although the core of the experimental setup is the same as before, the samples and the experimental technique are modified to work in an isoelectronic configuration, i.e. an approach where the Casimir and electrostatic forces are minimized in an attempt to enhance the effect of weak, hypothetical, forces. I will describe our current experimental results and the limits set on the strength and range of hypothetical new forces correcting the Newtonian gravitational potential.
Work was done in collaboration with D. López, H. B. Chan, E. Fischbach, D. E. Krause, G. Klimchitskaya and V. M. Mostepanenko.