TY - JOUR
T1 - Negative-continuum effects on the two-photon decay rates of hydrogenlike ions
AU - Surzhykov, Andrey
AU - Santos, José Paulo
AU - Amaro, Pedro
AU - Indelicato, Paul
N1 - A. S. acknowledges support from the Helmholtz Gemeinschaft and GSI under the Project No. VH-NG-421 and from the Deutscher Akademischer Austauschdienst (DAAD) under the Project No. 0813006. This research was supported in part by FCT Project No. POCTI/0303/2003 (Portugal), financed by the European Community Fund FEDER, by the French-Portuguese collaboration (PESSOA Program, Contract No. 441.00), and by the Accoes Integradas Luso-Francesas (Contract No. F-11/09) and Luso-Alemas (Contract No. A-19/09). Laboratoire Kastler Brossel is Unite Mixte de Recherche du CNRS, de l' ENS et de l' UPMC No. 8552. P. A. acknowledges the support of the FCT, under Contract No. SFRH/BD/37404/ 2007. This work was also partially supported by Helmholtz Alliance Grant No. HA216/EMMI.
PY - 2009/11/30
Y1 - 2009/11/30
N2 - Two-photon decay of hydrogenlike ions is studied within the framework of second-order perturbation theory, based on the relativistic Dirac'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 2 s1/2 →1 s1/2 and 2 p1/2 →1 s1/2 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's spectrum should be properly taken into account both for high- Z and low- Z atomic systems.
AB - Two-photon decay of hydrogenlike ions is studied within the framework of second-order perturbation theory, based on the relativistic Dirac'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 2 s1/2 →1 s1/2 and 2 p1/2 →1 s1/2 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's spectrum should be properly taken into account both for high- Z and low- Z atomic systems.
UR - http://www.scopus.com/inward/record.url?scp=70849111036&partnerID=8YFLogxK
U2 - 10.1103/PhysRevA.80.052511
DO - 10.1103/PhysRevA.80.052511
M3 - Article
AN - SCOPUS:70849111036
SN - 1050-2947
VL - 80
JO - Physical Review A - Atomic, Molecular, and Optical Physics
JF - Physical Review A - Atomic, Molecular, and Optical Physics
IS - 5
M1 - 052511
ER -