Related papers: Precision calculation of hyperfine structure of $^…
Transition frequencies and fine-structure splittings of the $2\,{}^3\!S_1 \rightarrow 2\,{}^3\!P_{\!J}$ transitions in helium-like $^{12}\mathrm{C}^{4+}$ were measured by collinear laser spectroscopy on a 1-ppb level. Accuracy is increased…
The results of investigations of the relativistic $^9$Be nucleus fragmentation in emulsion which entails the production of two He fragments of an energy of 1.2~A~GeV are presented. The results of the angular measurements of the…
Nuclear quadrupole moments ($Q$s) in three isotopes of potassium (K) with atomic mass numbers 39, 40 and 41 are evaluated more precisely in this work. The $Q$ value of $^{39}$K is determined to be 0.0614(6) $b$ by combining the available…
We consider higher-order corrections to hyperfine coefficients related to the spin-orbit and spin-spin tensor interactions in hydrogen molecular ions. The $m\alpha^7 \ln(\alpha)$-order radiative correction is derived in the NRQED framework.…
We measure hyperfine structure in the metastable ${^3P}_2$ state of $^{173}$Yb and extract the nuclear magnetic octupole moment. We populate the state using dipole-allowed transitions through the ${^3P}_1$ and ${^3S}_1$ states. We measure…
The \textit{ab initio} approach is used to evaluate the excitation energies of the $2s2p \, ^{2S+1}P_J$ states from the ground state as well as the $2s2p \, ^3P_1 \rightarrow 2s2p \, ^3P_0$ and $2s2p \, ^3P_2 \rightarrow 2s2p \, ^3P_1$…
Relativistic self-consistent-field calculations of the radial hyperfine integrals have been performed in the 4d-shell element ions. The comparison with available experimental results gives an estimate of configuration interaction effects in…
We employ an all-particle multireference Fock-space relativistic coupled-cluster (FSRCC) theory to compute the ionization potential, excitation energy, transition rate and hyperfine structure constants associated with…
Terms contributing to the hyperfine structure of the muonium ground state at the level of few tenths of kHz have been evaluated. The $\alpha^2 (Z\alpha)$ radiative correction has been calculated numerically to the precision of 0.02 kHz.…
Improved theoretical predictions for the fine-structure splitting of $2^3P_J$ levels in helium are obtained by the calculation of contributions of order $\alpha^5 Ry$. New results for transition frequencies, $\nu_{01} = 29 616 943.01(17)$…
The fully relativistic theory of the Zeeman splitting of the $1s$ hyperfine structure levels in hydrogenlike ions is considered for the magnetic field magnitude in the range from 1 to 10 T. The second-order corrections to the Breit -- Rabi…
The neutron--$^9$Li interaction and the corresponding low-energy $^{10}$Li spectrum are decisive for the properties of $^{11}$Li described as a three-body system (n+n+$^{9}$Li). We compute structure and breakup properties of $^{11}$Li as…
Optical atomic clocks using highly-charged ions hold an intriguing promise of metrology at the 19th significant figure. Here we study transitions within the $4f^{12}$ ground-state electronic configuration of highly charged ions. We consider…
The values of nuclear electric quadrupole moment are different by about 7% for 87Sr nucleus between the recommended value [N. J. Stone, At. Data Nucl. Data Tables 111-112, 1 (2016); P. Pyykko, Mol. Phys. 116, 1328 (2018)] and earlier…
Corrections of orders alpha^5, alpha^6 are calculated in the hyperfine splitting of the 2S state in the muonic hydrogen. The nuclear structure effects are taken into account in the one- and two-loop Feynman amplitudes by means of the proton…
Calculational results are presented for the fine-structure splitting of the 2^3P state of helium and helium-like ions with the nuclear charge Z up to 10. Theoretical predictions are in agreement with the latest experimental results for the…
Collinear laser spectroscopy measurements were performed on $^{69,71,73}$Ge isotopes ($Z = 32$) at ISOLDE-CERN. The hyperfine structure of the $4s^2 4p^2 \, ^3P_1 \rightarrow 4s^2 4p 5s \, ^3P_1^o$ transition of the germanium atom was…
This article contains a discussion in which we showed that observation of splitting in the energy levels of prolate nuclei, is possible. Similar effects is atomic physics is known as Zeeman effect which is well-known, but in nuclear physics…
A hydrogen-like atom consisting of a positive muon and an electron is known as muonium. It is a near-ideal two-body system for a precision test of bound-state theory and fundamental symmetries. The MuSEUM collaboration performed a new…
The charge topology of peripheral fragmentation of 1.2 A GeV $^7$Be nuclei in a nuclear emulsion is presented. The dissociation of $^7$Be nuclei via the channels $^7$Be$\rightarrow ^4$He + $^3$He, $^7$Be$\rightarrow$2$^3$He + n and…