  The axion is a hypothesized particle appearing in various theories beyond the
Standard Model. It is a light spin-0 boson initially postulated to solve the
strong CP problem and is also a strong candidate for dark matter. If the axion
or an axion-like particle exists, it would mediate a P-odd and T-odd
spin-dependent interaction. We describe two experiments under development at
Indiana University-Bloomington to search for such an interaction.
