Experimental Tests Of The Intermediate-Range Interactional Force At Submillimeters

As we know, there are four kinds of basic interactions in nature, they are long-range electromagnetisms interaction , universal gravitation, and the weak interaction of and strong one of the short distance. Is there the intermediate-range composition-dependent force (usually called the fifth force)? Is there also other basic interaction? This is one of the fundamental problems in physics.We carried out an experiment of detecting the possible existence of the intermediate-range composition-dependent at the ranges of submillimeters. Our expected results will provide a necessity of experiment basis for various theories. An extraordinary sensitive torsion balance was used to search for the new interaction. To maximize the effect, flat disk geometry is used for both the source and test masses which were all high density, and symmetry structure. The system shape can also greatly suppress Newtonian forces relative to the new intermediate-range effects. With help of the capacitive feedback control system, the torsion balance will be maintained in its initial equilibrium state by the parallel capacitive plates. A one-freedom platform driven by the sensitivity step motor was used to adjust the distance between the attracting and test masses. Our expected results will set new constraints on the possible intermediate-range composition-dependent interaction at scale of 0.5mm.This work is partially supported by the National Project for the Development of Key Fundamental Science in China (2003CB716305), and the National Natural Science Foundation of China (NSFC:10121503)...