Atoms and molecules can serve as sensitive probes of a possible variation of the fine structure constant α and electron‐to‐proton mass ratio μ. Two types of sensitivity coefficients are often used to ...quantify and compare the sensitivity of different species to the variation of fundamental constants. The dimensionless coefficients K are related to the fractional sensitivity, while dimensional factors q are related to the absolute sensitivity. Here, several common errors and misconceptions regarding these coefficients that frequently appear in the literature are discussed.
Atoms and molecules serve as probes of a possible variation of the fine structure constant and electron‐to‐proton mass ratio. Two types of coefficients are used to quantify sensitivity of different species to such variation. The dimensionless coefficients are related to the fractional sensitivity, while dimensional factors are related to the absolute sensitivity. Common errors regarding these coefficients are addressed.
Various fundamental-physics experiments such as measurement of the magnetic birefringence of the vacuum, searches for ultralight dark-matter particles (e.g., axions), and precision spectroscopy of ...complex systems (including exotic atoms containing antimatter constituents) are enabled by high-field magnets. We give an overview of current and future experiments and discuss the state-of-the-art DC- and pulsed-magnet technologies and prospects for future developments.
Basis Set Calculations of Heavy Atoms Kozlov, Mikhail G.; Demidov, Yuriy A.; Kaygorodov, Mikhail Y. ...
Atoms,
01/2024, Letnik:
12, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Most modern calculations of many-electron atoms use basis sets of atomic orbitals. An accurate account for electronic correlations in heavy atoms is a very difficult computational problem, and an ...optimization of the basis sets can reduce computational costs and increase final accuracy. Here, we propose a simple differential ansatz to form virtual orbitals from the Dirac–Fock orbitals of the core and valence electrons. We use basis sets with such orbitals to calculate different properties in Cs including hyperfine structure constants and QED corrections to the valence energies and to the E1 transition amplitudes.
Fast Apparent Oscillations of Fundamental Constants Antypas, Dionysios; Budker, Dmitry; Flambaum, Victor V. ...
Annalen der Physik,
April 2020, 2020-04-00, 20200401, Letnik:
532, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Precision spectroscopy of atoms and molecules allows one to search for and to put stringent limits on the variation of fundamental constants. These experiments are typically interpreted in terms of ...variations of the fine structure constant α and the electron‐to‐proton mass ratio μ=me/mp. Atomic spectroscopy is usually less sensitive to other fundamental constants, unless the hyperfine structure of atomic levels is studied. However, the number of possible dimensionless constants increases when allowed for fast variations of the constants, where “fast” is determined by the time scale of the response of the studied species or experimental apparatus used. In this case, the relevant dimensionless quantity is, for example, the ratio me/⟨me⟩ and ⟨me⟩ is the time average. In this sense, one may say that the experimental signal depends on the variation of dimensionful constants (me in this example).
The following scenario related to experimental searches for variations of fundamental constants is analyzed: The constants are allowed to vary fast, where “fast” is determined by the time scale of the response of the studied species or experimental apparatus used. It is shown that the number of varying constants increases in this “fast” regime, and that variation of dimensionful constants (in addition to dimensionless ones) can contribute to the experimental observable.
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