Muon g-2 and a Geocentric New Field

TL;DR

This paper explores how a hypothetical scalar field coupled to matter and spin could influence muon g-2 measurements and proposes experimental tests to detect such effects, challenging standard assumptions about axion constraints.

Contribution

It introduces a new scalar-mediated force affecting muon g-2 and suggests experimental approaches to test this hypothesis, differing from previous models.

Findings

Scalar force could cause measurable deviation in muon g-2

JPARC muon g-2 experiment can test the scalar coupling hypothesis

Proton electric dipole moment searches can constrain scalar-nucleon interactions

Abstract

Light scalars can in principle couple to both bulk matter and fermion spin, with hierarchically disparate strengths. Storage ring measurements of fermion electromagnetic moments via spin precession can be sensitive to such a force, sourced by the Earth. We discuss how this force could lead to a deviation of the measured muon anomalous magnetic moment, $g-2$, from the Standard Model prediction. Due to its different parameters, the proposed JPARC muon $g-2$ experiment can provide a direct test of our hypothesis. A future search for the proton electric dipole moment can have good sensitivity for the coupling of the assumed scalar to nucleon spin. We also argue that supernova constraints on axion-muon coupling may not be applicable in our framework.