2014/05/31 by Asimina Arvanitaki, Junwu Huang, Ken Van Tilburg · 3 citations
Physics and Astronomy · #hep-ph #hep-ex #physics.atom-ph #physics.optics
paper · pdf · doi:10.1103/physrevd.91.015015
published as PhysRevD.91.015015,2015 · 17 pages, 10 figures
arxiv created 2015/01/30 · arxiv updated 2015/02/03
We propose an experiment to search for ultralight scalar dark matter (DM) with dilatonic interactions. Such couplings can arise for the dilaton as well as for moduli and axion-like particles in the presence of CP violation. Ultralight dilaton DM acts as a background field that can cause tiny but coherent oscillations in Standard Model parameters such as the fine structure constant and the proton-electron mass ratio. These minute variations can be detected through precise frequency comparisons of atomic clocks. Our experiment extends current searches for drifts in fundamental constants to the well-motivated high-frequency regime. Our proposed setups can probe scalars lighter than 10-15 eV with discovery potential of dilatonic couplings as weak as 10-11 times the strength of gravity, improving current equivalence principle bounds by up to 8 orders of magnitude. We point out potential 104 sensitivity enhancements with future optical and nuclear clocks, as well as possible signatures in gravitational wave detectors. Finally, we discuss cosmological constraints and astrophysical hints of ultralight scalar DM, and show they are complimentary to and compatible with the parameter range accessible to our proposed laboratory experiments.