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Proceedings Paper

Measurement of the fine-structure constant as a test of the standard model
Author(s): Richard Parker

Paper Abstract

Measurements of the fine-structure constant α require methods from across subfields and are thus powerful tests of the consistency of theory and experiment in physics. Using the recoil frequency of cesium-133 atoms in a matter-wave interferometer, we recorded the most accurate measurement of the fine-structure constant to date: α = 1/137.035999046(27) at 2.0 × 10^−10 accuracy. Using multiphoton interactions (Bragg diffraction and Bloch oscillations), we demonstrate the largest phase (12 million radians) of any Ramsey-Bordé interferometer and control systematic effects at a level of 0.12 part per billion. Comparison with Penning trap measurements of the electron gyromagnetic anomaly ge − 2 via the Standard Model of particle physics is now limited by the uncertainty in ge − 2; a 2.5σ tension rejects dark photons as the reason for the unexplained part of the muon’s magnetic moment at a 99% confidence level. Implications for dark-sector candidates and electron substructure may be a sign of physics beyond the Standard Model that warrants further investigation.

Paper Details

Date Published: 5 March 2019
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Proc. SPIE 10934, Optical, Opto-Atomic, and Entanglement-Enhanced Precision Metrology, 1093424 (5 March 2019); doi: 10.1117/12.2515512
Show Author Affiliations
Richard Parker, Univ. of California, Berkeley (United States)


Published in SPIE Proceedings Vol. 10934:
Optical, Opto-Atomic, and Entanglement-Enhanced Precision Metrology
Selim M. Shahriar; Jacob Scheuer, Editor(s)

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