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The g Factor of the Bound Electron in Hydrogenlike Carbon



H Haeffner, N Hermanspahn, H -. Kluge, G Marx, W Quint, S Stahl, T Valenzuela, G Verdu, G Werth


The experimental determination of the magnetic moment of the bound electron in hydrogen-like ions is an important test of the theory of quantum electrodynamics in strong Coulomb fields. It represents a clean test of pure QED effects because it is not very sensitive to nuclear structure effects.In our experiment a single hydrogenlike carbon-ion is stored in a Penning trap, which consists of a strong magnetic field (4 T) and an electrostatic quadrupole potential. Due to the low background gas pressure in the cryopumped vacuum chamber (p -16 mbar) the storage time of the hydrogenlike carbon-ion is longer than one year. A new measurement technique has been developed, where the induction and detection of spin flips is spatially separated. This leads to an improvement in the measurement accuracy by 3 orders of magnitude. The new experimental value in the case of hydrogenlike carbon reads:g = 2.001 041 596 (1)(1)(4)The first error is the statistical uncertainty, the second error arises from possible systematic shifts and the third one denotes the uncertainty in the knowledge of the atomic mass of the electron. This result has to be compared to the theoretical valuewhich had been improved recently to an accuracy of about 10-9:g = 2.001 041 590 (1)(1)(1)where the uncertainties are due to the numerical accuracy of the one loop bound state QED calculations, to the nuclear recoil contribution and an estimation of the two loop bound state QED effects.The knowledge of the electron mass is therefore presently the main limitation to the interpretation of the g factor of hydrogenlike carbon as a test of bound state QED.
The g Factor of the Bound Electron in Hydrogenlike Carbon


bound electron, hydrogenlike carbon, magnetic moment, QED, quantum electrodynamics


Haeffner, H. , Hermanspahn, N. , Kluge, H. , Marx, G. , Quint, W. , Stahl, S. , Valenzuela, T. , Verdu, G. and Werth, G. (2001), The g Factor of the Bound Electron in Hydrogenlike Carbon, The g Factor of the Bound Electron in Hydrogenlike Carbon (Accessed March 3, 2024)
Created January 1, 2001, Updated February 17, 2017