• DOI:10.1103/PhysRevLett.120.161801
• Corpus ID: 206309919

Improved Limits on Spin-Mass Interactions.

@article{Lee2018ImprovedLO,
  title={Improved Limits on Spin-Mass Interactions.},
  author={Junyi Lee and Attaallah Almasi and Michael V. Romalis},
  journal={Physical review letters},
  year={2018},
  volume={120 16},
  pages={
          161801
        }
}

• Junyi Lee, Attaallah Almasi, M. Romalis
• Published 9 January 2018
• Physics
• Physical review letters

Very light particles with CP-violating couplings to ordinary matter, such as axions or axionlike particles, can mediate long-range forces between polarized and unpolarized fermions. We describe a new experimental search for such forces between unpolarized nucleons in two 250 kg Pb weights and polarized neutrons and electrons in a ^{3}He-K comagnetometer located about 15 cm away. We place improved constraints on the products of scalar and pseudoscalar coupling constants, g_{p}^{n}g_{s}^{N}<4.2×10^{-30} and g_{p}^{e}g_{s}^{N}<1.7×10^{-30} (95% C.L.) for axionlike particle masses less than 10^{-6}  eV, which represents an order of magnitude improvement over the best previous neutron laboratory limit.