Enhanced Laboratory Sensitivity to Variation of the Fine-Structure Constant using Highly Charged Ions

AbstractRecent theoretical works have proposed atomic clocks based on narrow optical transitions in highly charged ions. The most interesting candidates for searches of physics beyond the Standard Model are those which occur at rare orbital crossings where the shell structure of the periodic table is reordered. There are only three such crossings expected to be accessible in highly charged ions, and hitherto none have been observed as both experiment and theory have proven difficult. In this work we observe an orbital crossing in a system chosen to be tractable from both sides: Pr$${}^{9+}$$9+. We present electron beam ion trap measurements of its spectra, including the inter-configuration lines that reveal the sought-after crossing. With state-of-the-art calculations we show that the proposed nHz-wide clock line has a very high sensitivity to variation of the fine-structure constant, $$\alpha$$α, and violation of local Lorentz invariance; and has extremely low sensitivity to external perturbations.

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Measurement of Wavelengths and Abundances from Solar Flare X-Ray Spectra

International Astronomical Union Colloquium ◽

10.1017/s0252921100085572 ◽

1984 ◽

Vol 86 ◽

pp. 151-153

Author(s):

J.F. Seely ◽

U. Feldman ◽

G.A. Doschek

Keyword(s):

Fine Structure ◽

Quantum Electrodynamics ◽

Energy Levels ◽

Structure Constant ◽

Fine Structure Constant ◽

Transition Energies ◽

X Ray ◽

Hydrogenic Ions ◽

Charged Ions ◽

Important Test

The measurement of transition energies in highly charged ions represents an important test of quantum electrodynamics (QED) in strong fields. The OED contributions to the hydrogenic transition energies increase as (αZ)4, where α is the fine structure constant and Z is the atomic number. Transitions in hydrogenic ions of sulfur, chlorine, argon, and iron have previously been measured to a precision of 100 ppm or better. These measurements are in satisfactory agreement with accurate calculations of the energy levels, and this confirms the calculation of the QED contributions to the energy levels of one-electron ions.

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New Limit on Space-Time Variations in the Proton-to-Electron Mass Ratio from Analysis of Quasar J110325-264515 Spectra

Symmetry ◽

10.3390/sym12030344 ◽

2020 ◽

Vol 12 (3) ◽

pp. 344

Author(s):

T. D. Le

Keyword(s):

Fine Structure ◽

Structure Constant ◽

Space Time ◽

Fine Structure Constant ◽

Electron Mass ◽

Mass Ratio ◽

Quasar Spectra ◽

Time Variations ◽

Using Data ◽

The Universe

Astrophysical tests of current values for dimensionless constants known on Earth, such as the fine-structure constant, α , and proton-to-electron mass ratio, μ = m p / m e , are communicated using data from high-resolution quasar spectra in different regions or epochs of the universe. The symmetry wavelengths of [Fe II] lines from redshifted quasar spectra of J110325-264515 and their corresponding values in the laboratory were combined to find a new limit on space-time variations in the proton-to-electron mass ratio, ∆ μ / μ = ( 0.096 ± 0.182 ) × 10 − 7 . The results show how the indicated astrophysical observations can further improve the accuracy and space-time variations of physics constants.

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Measurement of the running of the fine structure constant below 1 GeV with the KLOE detector

EPJ Web of Conferences ◽

10.1051/epjconf/201921802012 ◽

2019 ◽

Vol 218 ◽

pp. 02012

Author(s):

Graziano Venanzoni

Keyword(s):

Fine Structure ◽

Energy Region ◽

Direct Evidence ◽

Branching Ratio ◽

Structure Constant ◽

Fine Structure Constant ◽

Recent Measurement ◽

Single Measurement ◽

Lepton Universality ◽

Hadronic Contribution

I will report on the recent measurement of the fine structure constant below 1 GeV with the KLOE detector. It represents the first measurement of the running of α(s) in this energy region. Our results show a more than 5σ significance of the hadronic contribution to the running of α(s), which is the strongest direct evidence both in time-and space-like regions achieved in a single measurement. From a fit of the real part of Δα(s) and assuming the lepton universality the branching ratio BR(ω → µ+µ−) = (6.6 ± 1.4stat ± 1.7syst) · 10−5 has been determined

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