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Updated: Nov 28, 2025

Setting Limits on Supersymmetry Using Simplified Models
Published on: November 15, 2013
New Limits on Anomalous Spin-Spin Interactions
Attaallah Almasi1, Junyi Lee1, Himawan Winarto1
1Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
Abstract:
We report the results of a new search for long-range spin-dependent interactions using a Rb-^{21}Ne atomic comagnetometer and a rotatable electron spin source based on a SmCo_{5} magnet with an iron flux return. By looking for signal correlations with the orientation of the spin source we set new constraints on the product of the pseudoscalar electron and neutron couplings g_{p}^{e}g_{p}^{n}/ℏc<1.7×10^{-14} and on the product of their axial couplings g_{A}^{e}g_{A}^{n}/ℏc<5×10^{-42} to a new particle with a mass of less than about 1 μeV. Our measurements improve by about 2 orders of magnitude previous constraints on such spin-dependent interactions.
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