Description
A fifth fundamental force (as a deviation from Newtonian gravity) is predicted by several theories addressing, for instance, questions relative to the dark sector or the lack of a unified framework for General Relativity and the Standard Model. Probing the existence of a fifth force at the submicron scale is challenging because electromagnetic interactions (e.g., the Casimir-Polder potential acting on an atom near a macroscopic body) dominate and may shield new physics. We propose to constrain representative fifth-force models (chameleon and symmetron fields, axion-nucleon coupling, and Yukawa parametrization) using the diffraction of slow atoms by material transmission nanogratings. The diffraction patterns are strongly modified by both the Casimir-Polder and putative non-Newtonian potentials arising inside the slits. To minimize the effects of the Casimir-Polder potential while preserving the effects of the putative fifth force on the analyzed observable, we are working on a differential measurement comparing diffraction patterns across nanograting geometries. Preliminary theoretical constraints await experimental confirmation. Thus, prospects include the fabrication of the nanogratings, a metrological measurement of the Casimir-Polder potential, and experimental tests of fifth-force models.