Vladimir I. Korobov

Nonrelativistic ionization energy for the helium ground state

The helium ground-state nonrelativistic energy with 24 significant digits is presented. The calculations are based on variational expansion with randomly chosen exponents. This data can be used as a benchmark for other approaches for many-electron and/or three-body systems.

Relativistic corrections ofmα6order to the rovibrational spectrum ofH2+andHD+molecular ions

The major goal of the high-precision studies of ro-vibrational states in the hydrogen molecular ions is to provide an alternative way for improving the electron-to-proton mass ratio, or the atomic mass of electron. By now the complete set of relativistic and radiative corrections have been obtained for a wide range of ro-vibrational states of H_2^+ and HD^+ up to order R_\infty\alpha^4. In this work we complete calculations of various contributions to the R_\infty\alpha^4 order by computing the relativistic corrections to the binding energy of electron.

Ionization Potential of the Helium Atom

The ground-state ionization potential of the He4 atom is found to be 5 945 204 223 (42) MHz. Along with lower-order contributions, this result includes all effects of relative order alpha4, alpha(3)m(e)/m(alpha), and alpha(5)ln(2)alpha. Effective operators derived in dimensionally regularized nonrelativistic quantum electrodynamics are employed. The average values of these operators are evaluated using a high-accuracy variational wave function constructed in an exponential basis.

Magnetic field effects in the transitions of the HD + molecular ion and precision spectroscopy

We analyse the effects of an external magnetic field on the ro-vibrational, rotational and radiofrequency transitions of the HD+ molecular ion—an important systematic effect in precision spectroscopy of HD+, which is of interest for metrology of the fundamental constants. The effects of an external magnetic field on the ro-vibrational, rotational and radiofrequency (hyperfine) transitions of the HD+ molecular ion are considered, for one-photon and, where relevant, two-photon transitions. The hyperfine structure of the spectrum lines is taken into account. Particular attention has been devoted to those transitions which are most insensitive to the magnetic field and its orientation with respect to the polarization of the radiation field. We identify experimentally accessible two-photon transitions that exhibit no Zeeman shift, one-photon and two-photon transitions that provide symmetrically split doublets, and one-photon transitions that show only a very weak quadratic Zeeman shift. The importance of the spin-stretched states is emphasized. The results can be used to determine the most suitable transitions given the experimental conditions.

Calculation of transition probabilities and ac Stark shifts in two-photon laser transitions of antiprotonic helium

Numerical ab initio variational calculations of the transition probabilities and ac Stark shifts in two-photon transitions of antiprotonic helium atoms driven by two counter-propagating laser beams are presented. We found that sub-Doppler spectroscopy is, in principle, possible by exciting transitions of the type

Relativistic corrections of m α 6 ( m ∕ M ) order to the hyperfine structure of the H 2 + molecular ion

(n,L)\ensuremath{\rightarrow}(n\ensuremath{-}2,L\ensuremath{-}2)

Theoretical Hyperfine Structure of the Molecular Hydrogen Ion at the 1 ppm Level.

between antiprotonic states of principal and angular momentum quantum numbers

Fundamental Transitions and Ionization Energies of the Hydrogen Molecular Ions with Few ppt Uncertainty

n~L\ensuremath{-}1~35

Hydrogen molecular ions for improved determination of fundamental constants

, first by using highly monochromatic, nanosecond laser beams of intensities

Vibrational spectroscopy of H 2 + : Hyperfine structure of two-photon transitions

{10}^{4}--{10}^{5}