| 释义 |
Lamb shift Physics.|læm ʃɪft|
[f. the name of Willis E. Lamb (b. 1913), U.S. physicist (who with R. C. Retherford demonstrated the effect in 1947) + shift n.]
A displacement of energy levels in hydrogen and hydrogen-like atoms such that those with the same values of the quantum numbers n and j but different values of l are not coincident, as predicted by Dirac's theory, but separated by a very small amount (the level with the lower value of l being the higher).
1948Physical Rev. LXXIV. 1157 The effects treated are the Lamb shift, the correction of the g-factor..and the correction of the Compton scattering cross section. 1950Ibid. LXXVII. 745 (heading) Departure of the Lamb shift from the h-3 law in He+. 1958Condon & Odishaw Handbk. Physics vii. iv. 63/1 The Lamb shift has been interpreted..as resulting from changes in the electron self-energy which results from its interactions with the electromagnetic and electron–positron fields. 1964E. A. Power Introd. Quantum Electrodynamics i. 7 The modern versions of quantum electrodynamics have enabled a very accurate comparison to be made between theory and experiment. Well-known examples are the Lamb shift energy splitting of the 2S½ and 2P½ levels in hydrogen and the radiative corrections to the magnetic moment of the electron. 1970G. K. Woodgate Elem. Atomic Struct. iv. 69 Figure 4.3 shows the fine structure of the n = 2 and n = 3 levels of hydrogen, modified to take account of the Lamb shift. 1973McGraw-Hill Yearbk. Sci. & Technol. 111/1 Experimental programs to measure heavy-ion Lamb shifts are now in progress. |