Polarized 3He as a probe for short-range spin-dependent interactions

TL;DR

This paper introduces a highly sensitive method using polarized helium-3 gas to detect short-range spin-dependent interactions, providing improved constraints on axion-like particle couplings at sub-millimeter scales.

Contribution

The study links spin-relaxation rates to short-range interactions, enabling a new technique to probe magnetic properties at very small scales with enhanced sensitivity.

Findings

Established a relationship between spin-relaxation and interaction properties.

Achieved a two-order-of-magnitude improvement in constraining axion-like interactions.

Demonstrated the method's potential for sub-millimeter magnetic property measurements.

Abstract

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 sub-millimeter scale, which are difficult to access by other means. The method has been used as a probe for nucleon-nucleon axion-like P,T violating interactions which yields a two-order-of-magnitude improved constraint on the coupling strength ($g_s g_p$) as a function of the force range ($\lambda$): $g_s g_p \lambda^2 < 3 \times 10^{-27}$ m$^2$.