Constraints on Exotic Dipole-Dipole Couplings between Electrons at the Micrometer Scale
Shlomi Salman Kotler, R. Ozeri, Derek F. Kimball
New constraints on exotic dipole-dipole interactions between electrons at the micrometer scale are established, based on a recent measurement of the magnetic interaction between two trapped 88Sr+ ions. For light bosons (mass ≤ 0.1 eV) we obtain 90% confidence intervals on pseudo-scalar and axial-vector mediated interaction strengths of |gPe gPe /4πc| ≤ 1.5 × 10−3 and |gAe 4πc| ≤ 1.2 × 10−17, respectively. These bounds significantly improve on previous work for this mass range. Assuming CPT invariance, these constraints are compared to those on anomalous electron-positron interactions, derived from positronium hyperfine spectroscopy. For axial-vector mediated interac- tion the electron-electron constraints are six orders of magnitude more stringent than the electron- positron constraints. Bounds on torsion gravity are also derived and compared with previous work performed at different length scales.