Search

Spectroscopic properties, useful for plasma diagnostics and astrophysics, of a few rubidium-like ions are studied here. We choose one of the simplest, but correlationally challenging series where d- and f-orbitals are present in the core and/or valence shells with as the ground state. We study different correlation characteristics of this series and make precise calculations of electronic structure and rates of electromagnetic transitions. Our calculated lifetimes and transition rates are compared with other available experimental and theoretical values. Radiative rates of vacuum ultraviolet electromagnetic transitions of the long lived Tc6+ ion, useful in several areas of physics and chemistry, are estimated. To the best of our knowledge, there is no literature for most of these transitions. [ABSTRACT FROM AUTHOR]

Previous studies show that within paraxial limit and electric dipole approximations, the orbital angular momentum (OAM) of a Laguerre–Gaussian (LG) beam rotates the whole atom about the beam axis but does not affect the internal electronic motion. The contribution of the Gaussian part of the LG beam profile to the angular momentum exchange is not usually taken into account. In this paper, we develop a theory which shows that not only the OAM of a LG beam, but also the geometry of the beam cross section, plays an important role in the electronic lowest-order transitions in the interaction of the beam with a trapped Rydberg atom, due to the large span of its electronic wavefunctions. In this interaction, the standard dipole selection rules do not hold and our results show that the otherwise forbidden transitions can become sufficiently probable. [ABSTRACT FROM AUTHOR]

This work presents precise calculations of important electromagnetic transition amplitudes along with details of their many-body correlations using the relativistic coupled-cluster method. Studies of hyperfine interaction constants, useful for plasma diagnostics, with this correlation exhaustive many-body approach, are another important area of this work. The calculated oscillator strengths of allowed transitions, amplitudes of forbidden transitions and lifetimes are compared with the other theoretical results wherever available and they show a good agreement. Hyperfine constants of different isotopes of W VI, presented in this paper, will be helpful in gaining an accurate picture of the abundances of this element in different astronomical bodies. [ABSTRACT FROM AUTHOR]

The astrophysically important electric quadrupole (E2) and magnetic dipole (M1) transitions for the low-lying states of triply ionized titanium (Ti IV) are calculated very accurately using a state-of-the-art all-order many-body theory called coupled cluster (CC) method in the relativistic framework. Different many-body correlations of the CC theory has been estimated by studying the core and valence electron excitations to the unoccupied states. The calculated excitation energies of different states are in excellent agreement with the measurements. Also, we compare our calculated electric dipole (E1) amplitudes of few transitions with recent many-body calculations by others. The lifetimes of the low-lying states of Ti IV have been estimated and long lifetime is found for the first excited 3d2D5/2 state, which suggested that Ti IV may be one of the useful candidates for many fundamental studies of physics. Most of the forbidden transition results reported here are not available in the literature, to the best of our knowledge. [ABSTRACT FROM AUTHOR]

This work presents accurate ab initio determination of the magnetic dipole (M1) and electric quadrupole (E2) hyperfine structure constants for the ground and a few low-lying excited states in 67Zn+, which is one of the interesting systems in fundamental physics. The coupled-cluster (CC) theory within the relativistic framework has been used here in these calculations. Long-standing demands for a relativistic and highly correlated calculation like CC can be able to resolve the disagreements among the lifetime estimations reported previously for a few low-lying states of Zn+. The roles of different electron correlation effects in the determination of these quantities are discussed and their contributions are presented. [ABSTRACT FROM AUTHOR]