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arXiv · 0908.2498

Negative continuum effects on the two-photon decay rates of hydrogen-like ions

A. Surzhykov·J. P. Santos·P. Amaro·Paul Indelicato
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Abstract

Two--photon decay of hydrogen--like ions is studied within the framework of second--order perturbation theory, based on relativistic Dirac's equation. Special attention is paid to the effects arising from the summation over the negative--energy (intermediate virtual) states that occurs in such a framework. In order to investigate the role of these states, detailed calculations have been carried out for the $2s_{1/2} - 1s_{1/2}$ and $2p_{1/2} - 1s_{1/2}$ transitions in neutral hydrogen H as well as for hydrogen--like xenon Xe$^{53+}$ and uranium U$^{91+}$ ions. We found that for a correct evaluation of the total and energy--differential decay rates, summation over the negative--energy part of Dirac's spectrum should be properly taken into account both for high--$Z$ and low--$Z$ atomic systems.

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A. Surzhykov, J. P. Santos, P. Amaro, Paul Indelicato. 2009-08-18. Negative continuum effects on the two-photon decay rates of hydrogen-like ions. https://doi.org/10.1103/physreva.80.052511

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