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Positronium fine-structure spectroscopy and diagnosis of asymmetric resonance lines

Gurung and colleagues used laser-prepared metastable positronium, microwave transitions and annihilation-time detection to study the n=2 fine structure. Their 2021 analysis reported 18,501.02±0.57(stat)±0.323(syst) MHz for the 2³S₁ → 2³P₀ interval, approximately 4.2 standard deviations above its cited QED prediction under that error budget. The J=1 and J=2 spectra revealed asymmetric lines. A subsequent model by Akopyan and colleagues showed that frequency-dependent microwave reflections could produce shifts of several MHz, including shifts of apparently symmetric lines, exposing a systematic uncertainty beyond the earlier budget.

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Gurung and colleagues used laser-prepared metastable positronium, microwave transitions and annihilation-time detection to study the n=2 fine structure. Their 2021 analysis reported 18,501.02±0.57(stat)±0.323(syst) MHz for the 2³S₁ → 2³P₀ interval, approximately 4.2 standard deviations above its cited QED prediction under that error budget. The J=1 and J=2 spectra revealed asymmetric lines. A subsequent model by Akopyan and colleagues showed that frequency-dependent microwave reflections could produce shifts of several MHz, including shifts of apparently symmetric lines, exposing a systematic uncertainty beyond the earlier budget.

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Scientific scope

The reported frequencies depend on line-shape assumptions, magnetic-field extrapolation, laser alignment and electric-field and Doppler estimates. The detailed experiment added recoil Doppler uncertainty omitted in 2020 without changing its central value. Subsequent numerical modeling suggested a conservative reflection-related uncertainty of about 4 MHz; this is a model estimate, not a measured correction or a verified probability distribution. Unmodeled chamber elements prevent direct correction of the original data. The earlier 4.2-standard-deviation comparison therefore does not establish a surviving anomaly, new force or failure of QED. Asymmetric J=1 and J=2 fit centres are diagnostics, not reliable precise intervals. The modeled quantum-interference channels were too small to explain the MHz effects; other unmodeled mechanisms and later experimental comparisons remain open.

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People and systems

L. Gurung; T. J. Babij; S. D. Hogan; D. B. Cassidy; J. Pérez-Ríos

These are the listed authors of the cited contribution sources. Paper authorship does not quantify individual effort. An incomplete list is explicitly marked; same names are not automatically merged.

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English catalogue narrative

Positronium fine-structure spectroscopy and diagnosis of asymmetric resonance lines

Gurung and colleagues used laser-prepared metastable positronium, microwave transitions and annihilation-time detection to study the n=2 fine structure. Their 2021 analysis reported 18,501.02±0.57(stat)±0.323(syst) MHz for the 2³S₁ → 2³P₀ interval, approximately 4.2 standard deviations above its cited QED prediction under that error budget. The J=1 and J=2 spectra revealed asymmetric lines. A subsequent model by Akopyan and colleagues showed that frequency-dependent microwave reflections could produce shifts of several MHz, including shifts of apparently symmetric lines, exposing a systematic uncertainty beyond the earlier budget.

Scientific scope

The reported frequencies depend on line-shape assumptions, magnetic-field extrapolation, laser alignment and electric-field and Doppler estimates. The detailed experiment added recoil Doppler uncertainty omitted in 2020 without changing its central value. Subsequent numerical modeling suggested a conservative reflection-related uncertainty of about 4 MHz; this is a model estimate, not a measured correction or a verified probability distribution. Unmodeled chamber elements prevent direct correction of the original data. The earlier 4.2-standard-deviation comparison therefore does not establish a surviving anomaly, new force or failure of QED. Asymmetric J=1 and J=2 fit centres are diagnostics, not reliable precise intervals. The modeled quantum-interference channels were too small to explain the MHz effects; other unmodeled mechanisms and later experimental comparisons remain open.

Reading status

This is a source-linked WRS catalogue note. A full explanatory guide and independent scientific reconstruction have not been completed for this entry. Read the identified original work for its complete narrative and arguments.

People and systems

L. Gurung; T. J. Babij; S. D. Hogan; D. B. Cassidy; J. Pérez-Ríos

These are the listed authors of the cited contribution sources. Paper authorship does not quantify individual effort. An incomplete list is explicitly marked; same names are not automatically merged.

Original sources