title: Limits on exotic long-range spin-spin interactions of electrons.
abstract: We surrounded a rotating torsion pendulum containing 9.8×10(22) polarized electrons by 2 or 4 stationary sources, each with a net spin of 6.0×10(24) polarized electrons. Multiple source configurations gave sensitivity to hypothetical dipole-dipole, spin-dot-spin, and spin-cross-spin exchange interactions mediated by bosons with masses up to 20 μeV. For bosons with masses ≤0.1 μeV our null results for the dipole-dipole, spin-dot-spin, and spin-cross-spin forces imply 1σ upper limits on (g(P)(e))(2)/(ħc), (g(A)(e))(2)/(ħc) and (g(V)(e)g(A)(e))/(ħc) of 2.2×10(-16), 3.8×10(-40), and 1.2×10(-28), respectively. We also constrain, for the first time, any possible linear combination of static spin-spin interactions. In this case our upper limits relax to 5.6×10(-16), 9.8×10(-40), and 1.2×10(-28), respectively.
authors.affiliation: Center for Experimental Nuclear Physics and Astrophysics, Box 354290, University of Washington, Seattle, Washington 98195-4290, USA.
authors.forename: B R
authors.initials: BR
authors.lastname: Heckel
authors.forename: W A
authors.initials: WA
authors.lastname: Terrano
authors.forename: E G
authors.initials: EG
authors.lastname: Adelberger