The Lamb shift of the 1 state in hydrogen: Two-loop and three-loop contributions
Jun 26, 2019
6 pages
Published in:
- Phys.Lett.B 795 (2019) 432-437
- Published: Aug 10, 2019
e-Print:
- 1906.11105 [physics.atom-ph]
DOI:
- 10.1016/j.physletb.2019.06.023 (publication)
Report number:
- TUM-HEP-1179/18
View in:
Citations per year
Abstract: (Elsevier)
We consider the 1 s Lamb shift in hydrogen and helium ions, a quantity, required for an accurate determination of the Rydberg constant and the proton charge radius by means of hydrogen spectroscopy, as well as for precision tests of the bound-state QED. The dominant QED contribution to the uncertainty originates from α8m external-field contributions (i.e., the contributions at the non-recoil limit). We discuss the two- and three-loop cases and in particular, we revisit calculations of the coefficients B61,B60,C50 in standard notation.
We have found a missing logarithmic contribution of order α2(Zα)6m . We have also obtained leading pure self-energy logarithmic contributions of order α2(Zα)8m and α2(Zα)9m and estimated the subleading terms of order α2(Zα)7m , α2(Zα)8m , and α2(Zα)9m . The determination of those higher-order contributions enabled us to improve the overall accuracy of the evaluation of the two-loop self-energy of the electron.
We investigated the asymptotic behavior of the integrand related to the next-to-leading three-loop term (order α3(Zα)5m , coefficient C50 in standard notation) and applied it to approximate integration over the loop momentum. Our result for contributions to the 1 s Lamb shift for the total three loop next-to-leading term is (−3.3±10.5)(α3/π3)(Zα)5m .
Altogether, we have completed the evaluation of the logarithmic contributions to the 1 s Lamb shift of order α8m and reduced the overall α8m uncertainty by approximately a factor of three for H, D, and He + as compared with the most recent CODATA compilation.Note:
- 7 pages, 3 figures
- quantum electrodynamics: perturbation theory
- perturbation theory: higher-order
- p: charge radius
- helium: ion
- hydrogen: ion
- Lamb shift
- precision measurement
- atom: excited state
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Figures(3)
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