Electron-electron interaction in strong electromagnetic fields: the two-electron contribution to the ground-state energy in He-like uranium.
Radiative recombination transitions into the ground state of cooled bare and hydrogenlike uranium ions were measured at the storage ring ESR. By comparing the corresponding x-ray centroid energies, this technique allows for a direct measurement of the electron-electron contribution to the ionization potential in the heaviest He-like ions. For the two-electron contribution to the ionization potential of He-like uranium we obtain a value of 2248+/-9 eV. This represents the most accurate determination of two-electron effects in the domain of high-Z He-like ions, and the accuracy reaches already the size of the specific two-electron radiative QED corrections.
Gumberidze
A
A
Gesellschaft für Schwerionenforschung, 64291 Darmstadt, Germany and Institut für Kernphysik, University of Frankfurt, 60486 Frankfurt, Germany.
Stöhlker
Th
T
Banaś
D
D
Beckert
K
K
Beller
P
P
Beyer
H F
HF
Bosch
F
F
Cai
X
X
Hagmann
S
S
Kozhuharov
C
C
Liesen
D
D
Nolden
F
F
Ma
X
X
Mokler
P H
PH
Orsić-Muthig
A
A
Steck
M
M
Sierpowski
D
D
Tashenov
S
S
Warczak
A
A
Zou
Y
Y