Nuclear spin content and constraints on exotic spin-dependent couplings

Understand

There are numerous recent and ongoing experiments employing a variety of atomic species to search for couplings of atomic spins to exotic fields.

• In order to meaningfully compare these experimental results, the coupling of the exotic field to the atomic spin must be interpreted in terms of the coupling to electron, proton, and neutron spins.
• Traditionally, constraints from atomic experiments on exotic couplings to neutron and proton spins have been derived using the single-particle Schmidt model for nuclear spin.
• In this model, particular atomic species are sensitive to either neutron or proton spin couplings, but not both.