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Saint Petersburg, Russia

Korzinin E.Y.,Mendeleev Institute for Metrology | Ivanov V.G.,Pulkovo Observatory | Karshenboim S.G.,Max Planck Institute of Quantum Optics
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

Corrections to energy levels in light muonic atoms are investigated in order α2(Zα)4m. We pay attention to corrections which are specific for muonic atoms and include the electron vacuum polarization loop. In particular, we calculate relativistic and relativistic-recoil two-loop electron vacuum polarization contributions. The results are obtained for the levels with n=1, 2 and in particular for the Lamb shift (2p1/2-2s1/2) and fine-structure intervals (2p3/2-2p1/2) in muonic hydrogen, deuterium, and muonic helium ions. © 2013 American Physical Society. Source


Karshenboim S.G.,Max Planck Institute of Quantum Optics | Ivanov V.G.,Pulkovo Observatory | Korzinin E.Y.,Mendeleev Institute for Metrology
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

The relativistic recoil contributions to the Uehling corrections are revisited. A controversy in recent calculations is considered, which is based on different approaches including Breit-type and Grotch-type calculations. It is found that calculations in those works were in fact done in different gauges and in some of those gauges contributions to retardation and two-photon-exchange effects were missed. Such effects are evaluated and a consistent result is obtained. A correct expression for the Grotch-type approach is presented, which produces a correct gauge-invariant result. A finite-nuclear-size correction for the Uehling term is also considered. The results are presented for muonic hydrogen and deuterium atoms and for muonic 3He and 4He ions. © 2012 American Physical Society. Source


Burmistrova N.A.,Mendeleev Institute for Metrology
Measurement Techniques | Year: 2015

An algorithm is proposed for evaluating inconsistent measurement data obtained in key comparisons of national standards. It is based on the procedure of modifying the measurement uncertainty in a way so as to form a set of metrologically compatible measurement results. Application of this algorithm is illustrated for the example of the CCQM-K5 key comparisons. The algorithm is compared with other methods. © 2015, Springer Science+Business Media New York. Source


Karpeshin F.F.,Mendeleev Institute for Metrology | Trzhaskovskaya M.B.,RAS Petersburg Nuclear Physics Institute
Nuclear Physics A | Year: 2015

Description of the Bohr-Wesskopf effect in the hyperfine structure of few-electron heavy ions is a challenging problem, which can be used as a test of both QED and atomic calculations. However, for twenty years the research has actually been going in a wrong direction, aimed at fighting the Bohr-Weisskopf effect through its cancellation in specific differences. Alternatively, we propose the constructive model-independent way, which enables the nuclear radii and their momenta to be retrieved from the hyper-fine splitting (HFS). The way is based on analogy of HFS to internal conversion coefficients, and the Bohr-Weisskopf effect - to the anomalies in the internal conversion coefficients. It is shown that the parameters which can be extracted from the data are the even nuclear momenta of the magnetization distribution. The radii R2 and - for the first time - R4 are obtained in this way by analysis of the experimental HFS values for the H- and Li-like ions of 209Bi. The critical prediction concerning the HFS for the 2p12 state is made. The present analysis shows high sensitivity of the method to the QED effects, which offers a way of precision test of QED. Experimental recommendations are given, which are aimed at retrieving data on the HFS values for a set of a few-electron configurations of each atom. © 2015 Elsevier B.V. Source


Karshenboim S.G.,Max Planck Institute of Quantum Optics | Ivanov V.G.,Pulkovo Observatory | Korzinin E.Y.,Mendeleev Institute for Metrology
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2014

Recently we calculated relativistic recoil corrections to the energy levels of the low-lying states in muonic hydrogen induced by electron vacuum polarization effects. The results were obtained by Breit-type and Grotch-type calculations. The former were described in our previous papers in detail, and here we present the latter. The Grotch equation was originally developed for pure Coulomb systems and allowed to express the relativistic recoil correction to order (Zα)4m2/M in terms of the relativistic nonrecoil contribution (Zα)4m. Certain attempts to adjust the method to electronic vacuum polarization took place in the past, however, the consideration was incomplete and the results were incorrect. Here we present a Grotch-type approach to the problem and in a series of papers consider relativistic recoil effects in order α(Zα)4m2/M and α2(Zα)4m2/M. That is the first paper of the series and it presents a general approach, while two other papers present results of calculations of the α(Zα)4m2/M and α2(Zα)4m2/ M contributions in detail. In contrast to our previous calculation, we address now a variety of states in muonic atoms with a certain range of the nuclear charge Z. © 2014 American Physical Society. Source

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