Andrew Geraci, University of Nevada Reno
Several tabletop low-energy experiments are posed to discover a wide range of new physics beyond the Standard model, where feeble interactions require precision measurements rather than high energies. In our experiments, high-Q resonant sensors enable ultra-sensitive force and field detection. In this talk I will describe two applications of these sensors in searches for new physics, based on techniques in atomic-molecular-and optical (AMO) physics. First, I will discuss an experiment which uses laser-cooled optically trapped silica nanospheres to search for corrections to Newtonian gravity at micron distances. In high vacuum, optically levitated dielectric particles achieve excellent decoupling from their environment and experience minimal friction. Hence they can be used for such sensitive force measurements, as well as searches for high-frequency gravitational waves. Second, I will discuss a new precision magnetometry experiment to search for a notable dark-matter candidate: the QCD axion. The Axion Resonant InterAction Detection Experiment (ARIADNE) is a collaborative effort to search for short-range spin-dependent couplings between nuclei resulting from axion exchange, using a technique based on nuclear magnetic resonance. The aim is to detect monopole-dipole interactions between the spin of laser-polarized 3He nuclei and a rotating unpolarized tungsten attractor. I will discuss the basic principle of the experiment and its current status.