S. G. Karshenboim

Publications (4)1.88 Total impact

• Article: Narrow atomic transitions with enhanced sensitivity to variation of the fine structure constant

  E J Angstmann, V A Dzuba, V V Flambaum, A Yu Nevsky, S G Karshenboim
  [show abstract] [hide abstract]
  ABSTRACT: To study the possible variation of the fine structure constant, α, in laboratory experiments, we propose using narrow lines that correspond to atomic transitions between close lying, long-lived atomic states of different configurations. The small transition frequency, coupled with differences in the electron structure ensures a strong enhancement of the relative frequency change compared to a possible change in α. The small linewidth makes it possible to perform very accurate measurements. These two features, when combined, make the measurements very sensitive to any variation of α.
  Journal of Physics B Atomic Molecular and Optical Physics 04/2006; 39(8):1937. · 1.88 Impact Factor
• Source

  Available from: V. A. Dzuba

  Article: A New Option for a Search for Alpha Variation: Narrow Transitions with Enhanced Sensitivity

  S. G. Karshenboim, A. Yu. Nevsky, E. J. Angstmann, V. A. Dzuba, V. V. Flambaum
  [show abstract] [hide abstract]
  ABSTRACT: We consider several transitions between narrow lines that have an enhanced sensitivity to a possible variation of the fine structure constant, alpha. This enhancement may allow a search to be performed with an effective suppression of the systematic sources of uncertainty that are unavoidable in conventional high-resolution spectroscopic measurements. In the future this may provide the strongest laboratory constraints on alpha variation.
  11/2005;
• Source

  Available from: arxiv.org

  Article: Limits on a Dynamically Varying Fine Structure Constant

  E. J. Angstmann, V. V. Flambaum, S. G. Karshenboim
  [show abstract] [hide abstract]
  ABSTRACT: We show that using the modified form of the Dirac Hamiltonian as suggested by Bekenstein, does not affect the analysis in [1-4] of QSO data pertaining to a measurement of alpha variation. We obtain the present time limit on Bekenstein's parameter, tan^{2}chi =(0.2 \pm 0.7)\times10^{-6}, from the measurement of the hydrogen 2p fine structure using value of alpha obtained from different experiments. Comment: references added, typos corrected
  07/2004;
• Source

  Available from: ArXiv

  Article: Cosmological Variation of the Fine Structure Constant versus a new Interaction

  E. J. Angstmann, V. V. Flambaum, S. G. Karshenboim
  [show abstract] [hide abstract]
  ABSTRACT: We show why a dynamically varying fine structure constant does not impact on the Webb group's analysis as suggested by Bekenstein. We also provide a limit on the size of a possible correction to the Dirac Hamiltonian caused by a perturbation due to a dynamically varying alpha in hydrogen.
  04/2004;