271 research outputs found
Quantum electrodynamics of heavy ions and atoms
The present status of quantum electrodynamics (QED) theory of heavy
few-electron ions is reviewed. The theoretical results are compared with
available experimental data. A special attention is focused on tests of QED at
strong fields and on determination of the fundamental constants. A recent
progress on calculations of the QED corrections to the parity nonconserving
6s-7s transition amplitude in neutral Cs is also discussed.Comment: Talk at ICAP 2006, Innsbruck, Austri
How to scrutinise a Production Sharing Agreement: A guide for the oil and gas sector based on experience from the Caspian region
This guide discusses the provisions of a particular type of oil and gas contract, the Production Sharing Agreement (PSA). While the guide is aimed at a general civil society readership, it draws particularly on experience from Kazakhstan. The purpose of this guide is to give an accessible account of some key characteristics of PSAs, with a focus on revenue issues, and to suggest action points for civil society organisations involved with monitoring extractive industries. Indeed, in recent years the public in resource-rich states has become increasingly concerned about the management of extractive industry revenues
QED calculation of the 2p3/2-2p1/2 transition energy in five-electron ion of argon
We perform ab initio QED calculation of the (1s)^2(2s)^22p_{3/2} -
(1s)^2(2s)^22p_{1/2} transition energy in the five-electron ion of argon. The
calculation is carried out by perturbation theory starting with an effective
screening potential approximation. Four different types of the screening
potentials are considered. The rigorous QED calculations of the two
lowest-order QED and electron-correlation effects are combined with approximate
evaluations of the third- and higher-order electron-correlation contributions.
The theoretical value for the wavelength obtained amounts to 441.261(70) (nm,
air) and perfectly agrees with the experimental one, 441.2559(1) (nm, air).Comment: 10 pages, 3 figures, 1 tabl
Nuclear recoil effect on the magnetic-dipole decay rates of atomic levels
The effect of finite nuclear mass on the magnetic-dipole transition
probabilities between fine-structure levels of the same term is investigated.
Based on a rigorous QED approach a nonrelativistic formula for the recoil
correction to first order in m_e/M is derived. Numerical results for
transitions of experimental interest are presented.Comment: 9 page
- …