Related papers: Limit on the Temporal Variation of the Fine-Struct…
The search for variation of the fundamental constants such as the fine structure constant $\alpha$ ($\alpha=e^2/\hbar c$) and the ratios of fundamental masses (e.g., electron to proton mass ratio $\mu=m_e/m_p$) is reviewed. Strong emphasis…
Dipole-dipole interactions lead to frequency shifts that are expected to limit the performance of next-generation atomic clocks. In this work, we compute dipolar frequency shifts accounting for the intrinsic atomic multilevel structure in…
High accuracy measurements in M\"ossbauer transitions open up the possibility to use them in the search for temporal and spatial variation of the fine-structure constant $\alpha$, quark mass $m_q$, and dark matter field which may lead to…
Theories unifying gravity with other interactions suggest spatial and temporal variation of fundamental ``constants'' in the Universe. A change in the fine structure constant, alpha, could be detected via shifts in the frequencies of atomic…
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…
An atom exposed to an electric field will experience Stark shifts of its internal energy levels, proportional to their polarizabilities. In optical frequency metrology, the Stark shift due to background black-body radiation (BBR) modifies…
The highly forbidden $^2$S$_{1/2} \rightarrow ^2$F$_{7/2}$ electric octupole transition in $^{171}$Yb$^+$ is a potential candidate for a redefinition of the SI second. We present a measurement of the absolute frequency of this optical…
Transition frequencies of atoms and ions are among the most accurately accessible quantities in nature, playing important roles in pushing the frontiers of science by testing fundamental laws of physics, in addition to a wide range of…
Sun's gravitation potential at earth varies during a year due to varying Earth-Sun distance. Comparing the results of very accurate measurements of atomic clock transitions performed at different time in the year allows us to study the…
We report new limits on ultralight scalar dark matter (DM) with dilaton-like couplings to photons that can induce oscillations in the fine-structure constant alpha. Atomic dysprosium exhibits an electronic structure with two nearly…
The dysprosium parity violation experiment concluded nearly 17 years ago with an upper limit on weak interaction induced mixing of nearly degenerate, opposite parity states in atomic dysprosium. While that experiment was limited in…
Configuration interaction in many-electron atoms may cause anomalies in the fine structure which make the intervals small and very sensitive to variation of the fine structure constant. Repeated precision measurements of these intervals…
We present a review of recent works devoted to the variation of the fine structure constant alpha, strong interaction and fundamental masses. There are some hints for the variation in quasar absorption spectra, Big Bang nucleosynthesis, and…
The 7.6 eV electromagnetic transition between the nearly degenerate ground state and first excited state in the Th-229 nucleus may be very sensitive to potential changes in the fine-structure constant, $\alpha = e^2/\hbar c$. However, the…
Atomic microwave clocks based on hyperfine transitions, such as the caesium standard, tick with a frequency that is proportional to the magnetic moment of the nucleus. This magnetic moment varies strongly between isotopes of the same atom,…
The absolute frequency of the $^{87}{\rm Sr}$ clock transition measured in 2015 was reevaluated using an improved frequency link to the SI second. The scale interval of International Atomic Time (TAI) that we used as the reference was…
We present new measurements of quantum defects and core polarizabilities in cesium ($^{133}$Cs), based on transition frequency measurements between Rydberg states ($14 \leq n \leq 38$) obtained through terahertz (THz) and radio-frequency…
Configuration interaction method is used to calculate transition amplitudes and other properties of the low states of dysprosium which are used in cooling and in study of the time variation of the fine structure constant and violation of…
We experimentally investigate an optical frequency standard based on the $^2S_{1/2} (F=0)\to {}^2F_{7/2} (F=3)$ electric octupole (\textit{E}3) transition of a single trapped $^{171}$Yb$^+$ ion. For the spectroscopy of this strongly…
Sensitivity to temporal variation of the fundamental constants may be strongly enhanced in transitions between narrow close levels of different nature. This enhancement may be realized in a large number of molecules due to cancelation…