Speaker
Description
A fifth force may arise due to “new physics” beyond the Standard Model. We focus on the spin-dependent fifth
forces that are mediated by new particles, such as spin-0 particles (axion and
axion-like particles) and spin-1 particles (e.g., light Z’ particle or massless
paraphoton). These new ultralight particles are also candidates for dark matter and
dark energy, and may also break fundamental symmetries. Spin-dependent
interactions between fermions have been extensively searched for in experiments,
employing methods such as comagnetometers, nitrogen-vacancy spin sensors,
and precision measurements of atomic and molecular spectra. Our
research involves a theoretical reassessment of exotic spin-dependent forces. It
produces a systematic and complete set of interaction potentials expressed in
terms of reduced coupling constants. We conduct an extensive analysis of the
existing body of experimental literature on spin-dependent fifth forces, which
produces systematic exclusion plots. This leads to a comprehensive understanding
of the current research landscape and provide insights for further research.
