Polarized 3He as a Probe for Short-Range Spin-Dependent Interactions

We have studied the relaxation of a spin-polarized gas in a magnetic field, in the presence of short-range spin-dependent interactions. As a main result we have established a link between the specific properties of the interaction and the dependence of the spin-relaxation rate on the magnitude of the holding magnetic field. This allows us to formulate a new, extremely sensitive method to study (pseudo) magnetic properties at the submillimeter scale, which are difficult to access by other means. The method has been used as a probe for nucleon-nucleon axionlike P, T violating interactions which yields a two-order-of-magnitude improved constraint on the coupling strength (g{sub s}g{sub p}) as a function of the force range ({lambda}): g{sub s}g{sub p{lambda}}{sup 2}<3x10{sup -27} m{sup 2}.