404 research outputs found
Atomic Parameters for the Transition of Ne I relevant in nuclear physics
We calculated the magnetic dipole hyperfine interaction constants and the
electric field gradients of and levels
of Ne I by using the multiconfiguration Dirac-Hartree-Fock method. The
electronic factors contributing to the isotope shifts were also estimated for
the nm transition connecting these two states. Electron
correlation and relativistic effects including the Breit interaction were
investigated in details. Combining with recent measurements, we extracted the
nuclear quadrupole moment values for Ne and Ne with a smaller
uncertainty than the current available data. Isotope shifts in the
transition based on the present
calculated field- and mass-shift parameters are in good agreement with the
experimental values. However, the field shifts in this transition are two or
three orders of magnitude smaller than the mass shifts, making rather difficult
to deduce changes in nuclear charge mean square radii. According to our
theoretical predictions, we suggest to use instead transitions connecting
levels arising from the configuration to the ground state, for which
the normal mass shift and specific mass shift contributions counteract each
other, producing relatively small mass shifts that are only one order of
magnitude larger than relatively large field shifts, especially for the
transition
Theoretical isotope shifts in neutral barium
The present work deals with a set of problems in isotope shifts of neutral
barium spectral lines. Some well known transitions
( and ) are first
investigated. Values of the changes in the nuclear mean-square charge radius
are deduced from the available experimental isotope shifts using our ab initio
electronic factors. The three sets
obtained from these lines are consistent with each other. The combination of
the available nuclear mean-square radii with our electronic factors for the
transitions produces isotope shift values in
conflict with the laser spectroscopy measurements of Dammalapati et al. (Eur.
Phys. J. D 53, 1 (2009))
Hyperfine induced 1s2s ^1S_0 \to 1s^2 ^1S_0 M1 transition of He-like ions
Hyperfine induced 1s2s ^1S_0 \to 1s^2 ^1S_0 M1 transition probabilities of
He-like ions have been calculated from relativistic configuration interaction
wavefunctions including the frequency independent Breit interaction and QED
effects. Present results for {}Eu and {}Gd are in good
agreement with previous calculations [Phys. Rev. A {\bf 63}, 054105 (2001)].
Electronic data are given in terms of a general scaling law in that, given
isotopic nuclear spin and magnetic moment, allows hyperfine induced decay rates
to be estimated for any isotope. The results should be helpful for future
experimental investigations on QED and parity non-conservation effects.Comment: 9 pages, 2 figure
- …