New determination of the fine structure constant from the electron value and QED.
Quantum electrodynamics (QED) predicts a relationship between the dimensionless magnetic moment of the electron (g) and the fine structure constant (alpha). A new measurement of g using a one-electron quantum cyclotron, together with a QED calculation involving 891 eighth-order Feynman diagrams, determine alpha(-1)=137.035 999 710 (96) [0.70 ppb]. The uncertainties are 10 times smaller than those of nearest rival methods that include atom-recoil measurements. Comparisons of measured and calculated g test QED most stringently, and set a limit on internal electron structure.
Gabrielse
G
G
Lyman Laboratory, Harvard University, Cambridge, Massachusetts 02138, USA.
Hanneke
D
D
Kinoshita
T
T
Nio
M
M
Odom
B
B