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Precision measurement of the 23S1→23P2 interval in positronium using phase-variation Ramsey spectroscopy

D. M. Newson and D. B. Cassidy

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Phys. Rev. A 114, 022821 – Published 24 August, 2026

DOI: https://doi.org/10.1103/668h-zh4w

Abstract

The 23S1→23P2 interval in positronium (Ps) has been measured using a phase-variation separated oscillatory fields method. The experiment was performed in a low-magnetic-field region using a beam of 23S1 atoms generated in a Xe gas cell via a charge exchange reaction. The Ps beam passed through two spatially separated microwave field regions whose relative phase was varied. The resonance frequency was obtained from the frequency dependence of the phase of the resulting interference signal, which was scanned over a range of less than 10 MHz. We obtained a value of 8626.82±0.48stat±0.05sysMHz, in good agreement with the theoretical value of 8626.78±0.08MHz calculated using O(meα6) QED theory.

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Phys. Rev. A 114, 022821– Published 24 August, 2026
  • Received 8 May 2026
  • Accepted 5 August 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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