<?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%">P Amaro</style></author><author><style face="normal" font="default" size="100%">J P Santos</style></author><author><style face="normal" font="default" size="100%">F. Parente</style></author><author><style face="normal" font="default" size="100%">A. Surzhykov</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%">Resonance effects on the two-photon emission from hydrogenic 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://journals.aps.org/pra/abstract/10.1103/PhysRevA.79.062504</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">6</style></number><volume><style face="normal" font="default" size="100%">79</style></volume><pages><style face="normal" font="default" size="100%">062504</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;A theoretical study of the all two-photon transitions from initial bound states with ni=2,3 in hydrogenic ions is presented. High-precision values of relativistic decay rates for ions with nuclear charge in the range 1&amp;lt;=Z&amp;lt;=92 are obtained through the use of finite basis sets for the Dirac equation constructed from B splines. We also report the spectral (energy) distributions of several resonant transitions, which exhibit interesting structures, such as zeros in the emission spectrum, indicating that two-photon emission is strongly suppressed at certain frequencies. We compare two different approaches (the line profile approach and the QED approach based on the analysis of the relativistic two-loop self-energy) to regularize the resonant contribution to the decay rate. Predictions for the pure two-photon contributions obtained in these approaches are found to be in good numerical agreement.&lt;/p&gt;
</style></abstract><notes><style face="normal" font="default" size="100%">&lt;p&gt;Webpage CFA-FCTUNLJPS-Ref36&lt;/p&gt;
</style></notes><custom3><style face="normal" font="default" size="100%">papers3://publication/uuid/A2E0270E-F74B-46ED-908A-BD6370BDC0B5</style></custom3><label><style face="normal" font="default" size="100%">r01113</style></label></record></records></xml>