<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">A. Surzhykov</style></author><author><style face="normal" font="default" size="100%">J P Santos</style></author><author><style face="normal" font="default" size="100%">P Amaro</style></author><author><style face="normal" font="default" size="100%">P. Indelicato</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Negative-continuum effects on the two-photon decay rates of hydrogenlike ions</style></title><secondary-title><style face="normal" font="default" size="100%">Physical Review A</style></secondary-title><short-title><style face="normal" font="default" size="100%">JPS_Articles</style></short-title></titles><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://link.aps.org/abstract/PRA/v80/e052511</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">5</style></number><publisher><style face="normal" font="default" size="100%">APS</style></publisher><volume><style face="normal" font="default" size="100%">80</style></volume><pages><style face="normal" font="default" size="100%">052511</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Two-photon decay of hydrogenlike ions is studied within the framework of second-order perturbation theory, based on the relativistic Dirac&amp;apos;s equation. Special attention is paid to the effects arising from the summation over the negative-energy (intermediate virtual) states that occur in such a framework. In order to investigate the role of these states, detailed calculations have been carried out for the 2s1/2--&amp;gt;1s1/2 and 2p1/2--&amp;gt;1s1/2 transitions in neutral hydrogen H as well as for hydrogenlike xenon Xe53+ and uranium U91+ ions. We found that for a correct evaluation of the total and energy-differential decay rates, summation over the negative-energy part of Dirac&amp;apos;s spectrum should be properly taken into account both for high-Z and low-Z atomic systems.&lt;/p&gt;
</style></abstract><notes><style face="normal" font="default" size="100%">&lt;p&gt;Webpage CFA-FCTUNLJPS-Ref39&lt;/p&gt;
</style></notes><custom3><style face="normal" font="default" size="100%">papers3://publication/uuid/7A6C2869-DF35-444B-B15B-F6ABA28F18A1</style></custom3><label><style face="normal" font="default" size="100%">r00973</style></label></record></records></xml>