We have extended two-photon Doppler-free spectroscopy to the vacuum ultraviolet spectral region, to accurately measure the He 11S-21S transition at 120 nm. Our result is 4984872315(48) MHz. This yields a ground state Lamb shift of 41104(48) MHz, in fair agreement with theory and other experiments. This approach has the potential for significantly better accuracy once improvements in the laser and the wavelength metrology are implemented.
Original Publication Citation
S. D. Bergeson, A. Balakrishnan, K. G. H. Baldwin, T. B. Lucatorto, J. P. Marangos, T. J. McIlrath, … E. E. Eyler. Measurement of the He ground state lamb shift via the two-photon 1(1)S-2(1)S transition. Phys. Rev. Lett. 80 (16), 3475-3478 (1998).
BYU ScholarsArchive Citation
Bergeson, Scott D.; Balakrishnan, A.; Baldwin, K. G. H.; Lucatorto, T. B.; Marangos, J. P.; McIlrath, T. J.; O'Brian, T. T.; Rolston, S. L.; Sansonetti, C. J.; Wen, Jesse; Westbrook, N.; Cheng, C. H.; and Eyler, E. E., "Measurement of the He Ground State Lamb Shift via the Two-Photon 1 1S-2 1S Transition" (1998). All Faculty Publications. 1831.
American Physical Society
Physical and Mathematical Sciences
Physics and Astronomy
© 1998 American Physical Society. This article is the Version of Record published by the American Physical Society in Physical Review Letters in 1998, available online at https://doi.org/10.1103/PhysRevLett.80.3475
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