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New Limits on Anomalous Spin-Spin Interactions
Attaallah Almasi1, Junyi Lee1, Himawan Winarto1
1Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
Physical Review Letters
|December 1, 2020
Summary
This study searched for long-range spin-dependent interactions using an atomic comagnetometer. New constraints were set on electron and neutron couplings, significantly improving previous limits for new particles.
Area of Science:
- Atomic physics
- Particle physics
- Quantum mechanics
Background:
- Searches for new fundamental interactions are crucial for extending the Standard Model.
- Atomic comagnetometers offer high sensitivity for detecting subtle spin-dependent forces.
Purpose of the Study:
- To search for new long-range spin-dependent interactions.
- To set improved experimental constraints on fundamental coupling constants.
Main Methods:
- Utilized a Rubidium-21Neon atomic comagnetometer.
- Employed a rotatable electron spin source utilizing a SmCo5 magnet.
Main Results:
- Established new constraints on pseudoscalar electron-neutron couplings: g_p^e g_p^n / ħc < 1.7x10^-14.
- Set new constraints on axial electron-neutron couplings: g_A^e g_A^n / ħc < 5x10^-42.
- Improved previous limits on spin-dependent interactions by approximately two orders of magnitude.
Conclusions:
- The experiment provides stringent new limits for new particles under 1 μeV.
- The results significantly advance the search for beyond-Standard-Model physics.
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