Using Geoelectrons to Search for Velocity-Dependent Spin-Spin Interactions

TL;DR

This paper uses Earth's electron spin model and laboratory experiment data to set new bounds on velocity-dependent spin-spin interactions, significantly improving constraints on these hypothetical forces.

Contribution

It introduces a novel method combining geoelectron-spin modeling with experimental data to constrain six possible long-range velocity-dependent spin-spin interactions.

Findings

Five of six potentials are now bounded for the first time.

The constraint on V8 is improved by about 30 orders of magnitude.

New bounds are established on interactions involving electron, neutron, and proton spins.

Abstract

We use the recently developed model of the electron spins within the Earth to investigate all of the six possible long-range velocity-dependent spin-spin interactions associated with the exchange of an intermediate vector boson. Several laboratory experiments have established upper limits on the energy associated with various fermion-spin orientations relative to the Earth. We combine the results from three of these experiments with the geoelectron-spin model to obtain bounds on the velocity-dependent interactions that couple electron spin to the spins of electrons, neutrons and protons. Five of the six possible potentials investigated were previously unbounded. The bound achieved on V8 is about 30 orders of magnitude more restrictive in the long-range limit than the only previously established constraint.