A new design for testing the gravitational inverse-square law at the sub-millimeter range with a 32-fold symmetric attractor

Abstract

Short-range tests of the gravitational inverse-square law are very important for finding new interactions. In order to further improve the constraints on the Yukawa-like gravitational force, we propose a new scheme based on the torsion balance, where the speculative Yukawa-like gravitational force between the pendulum and the attractor is substantially increased by increasing the area of the test mass and the source mass. A dual-compensation design is used to realize a null experiment, which can release the accuracy requirement on some geometric parameters. The calculation result shows that, at the 95% confidence level, the new design can establish the strongest bound on the magnitude α of the Yukawa violation at the range of 40–800 μm with the total error of about 2.0 × 10−17 N m, and improve the previous bounds about one order of magnitude at the length scale λ ≈ 300 μm.