V. M. Shabaev

Publications (142)167.16 Total impact

• Article: Parity-nonconservation effects on the radiative recombination of heavy hydrogenlike ions

  J. Gunst, A. Surzhykov, A. Artemyev, S. Fritzsche, S. Tashenov, A. Maiorova, V. M. Shabaev, Th. Stöhlker
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  ABSTRACT: Based on the theoretical analysis of the radiative recombination of heavy hydrogen-like ions with unpolarized electrons, a scheme is proposed for observing atomic parity nonconservation (PNC). The scheme employs the sensitivity of the polarization properties of recombination photons on the PNC-induced mixing of opposite-parity ionic levels. For the electron capture into the 1s2p 3P0 state of helium-like ions, in particular, the PNC leads to a rotation of the photon linear polarization on the angle, directly proportional to the 1s2p 3P0–1s2s 1S0 mixing parameter. Owing to the recent advances in the development of x-ray polarimeters, the observation of such a rotation angle and, hence, the corresponding parity mixing is likely to become feasible in the future.
  Physical Review A 03/2013; · 2.88 Impact Factor
• Article: g Factor of Lithiumlike Silicon ^{28}Si^{11+}.

  A Wagner, S Sturm, F Köhler, D A Glazov, A V Volotka, G Plunien, W Quint, G Werth, V M Shabaev, K Blaum
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  ABSTRACT: The g factor of lithiumlike silicon ^{28}Si^{11+} has been measured in a triple-Penning trap with a relative uncertainty of 1.1×10^{-9} to be g_{exp⁡}=2.000 889 889 9(21). The theoretical prediction for this value was calculated to be g_{th}=2.000 889 909(51) improving the accuracy to 2.5×10^{-8} due to the first rigorous evaluation of the two-photon exchange correction. The measured value is in excellent agreement with the theoretical prediction and yields the most stringent test of bound-state QED for the g factor of the 1s^{2}2s state and the relativistic many-electron calculations in a magnetic field.
  Physical Review Letters 01/2013; 110(3):033003. · 7.37 Impact Factor
• Article: 3. Double-beta transformations in isobaric triplets with mass numbers A=124, 130, and 136

  D. A. Nesterenko, K. Blaum, M. Block, C. Droese, S. Eliseev, F. Herfurth, E. Minaya Ramirez, Yu. N. Novikov, L. Schweikhard, V. M. Shabaev, M. V. Smirnov, I. I. Tupitsyn, K. Zuber, and N. A. Zubova
  10/2012;
• Article: Q value and half-life of double-electron capture in Os-184

  C. Smorra, T. R. Rodriguez, T. Beyer, K. Blaum, M. Block, Ch. E. Düllmann, K. Eberhardt, M. Eibach, S. Eliseev, K. Langanke, G. Martinez-Pinedo, Sz. Nagy, W. Nörtershäuser, D. Renisch, V. M. Shabaev, I. I. Tupitsyn, N. A. Zubova
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  ABSTRACT: Os-184 has been excluded as a promising candidate for the search of neutrinoless double-electron capture. High-precision mass measurements with the Penning-trap mass spectrometer TRIGA-TRAP resulted in a marginal resonant enhancement with = -8.89(58) keV excess energy to the 1322.152(22) keV 0+ excited state in W-184. State-of-the-art energy density functional calculations are applied for the evaluation of the nuclear matrix elements to the excited states predicting a strong suppression due to the large deformation of mother and daughter states. The half-life of the transition in Os-184 exceeds T_{1/2} > 1.3 10^{29} years for an effective neutrino mass of 1 eV.
  09/2012;
• Article: Production and diagnostics of spin-polarized heavy ions in sequential two-electron radiative recombination

  A. V. Maiorova, A. Surzhykov, S. Tashenov, V. M. Shabaev, Th. Stöhlker
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  ABSTRACT: In the present work we investigate the sequential radiative recombination (RR) of initially bare ions colliding with two spatially separated electron targets. It is shown that magnetic sublevel population of the hydrogenlike ions, produced by the electron capture from the first target, depends on the emission direction of the (first) RR photon. This population, which can be expressed in terms of the polarization parameters, affects then the angular and polarization properties of the radiation emitted in the collision with the second target. The coincidence measurements of two subsequent RR photons may allow one to understand, therefore, the production and diagnostics of the ion spin polarization. In order to describe this polarization production and diagnostic scheme we derive the general expression for the γ-γ correlation function. Detailed calculations for the dependence of this function on the geometry of photon emission and collision energy are performed for the radiative recombination of bare uranium ions.
  Physical Review A 09/2012; 86(3). · 2.88 Impact Factor
• Article: Tests of fundamental theories with heavy ions at low-energy regime

  D. A. Glazov, Y. S. Kozhedub, A. V. Maiorova, V. M. Shabaev, I. I. Tupitsyn, A. V. Volotka, C. Kozhuharov, G. Plunien, Th. Stöhlker
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  ABSTRACT: The current status of theoretical investigations of spectroscopic properties and fundamental interactions in highly charged ions is reviewed. Laying special attention on tests of quantum electrodynamics at strong fields recent progress in calculations of energy levels, hyperfine splitting and g factor values is reported. The parity nonconservation effect on the laser-induced 23S1-21S02^3S_1-2^1S_0 transition in heavy He-like ions is studied, which could serve as test scenario for the Standard Model in low-energy atomic physics. The Coulomb glory effect in collisions of antiprotons with heavy ions is considered. It is emphasized that observation of this effect in collisions of antiprotons with bare nuclei would exhibit the screening properties of the vacuum polarization potential. A new approach to the description of dynamic atomic processes in low-energy heavy-ion collisions is presented. As a first application of this approach, the charge transfer probabilities for the U91 + (1s) – U92 +  collision are evaluated. KeywordsQuantum electrodynamics–Highly charged ions–Lamb shift–Hyperfine splitting– g factor–Parity nonconservation effects–Antiproton scattering–Heavy ion collisions
  Hyperfine Interactions 04/2012; 199(1):71-83. · 0.21 Impact Factor
• Source

  Available from: Ilya Tupitsyn

  Article: Test of many-electron QED effects in the hyperfine splitting of heavy high-Z ions.

  A V Volotka, D A Glazov, O V Andreev, V M Shabaev, I I Tupitsyn, G Plunien
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  ABSTRACT: A rigorous evaluation of the two-photon exchange corrections to the hyperfine structure in lithiumlike heavy ions is presented. As a result, the theoretical accuracy of the specific difference between the hyperfine splitting values of H- and Li-like Bi ions is significantly improved. This opens a possibility for the stringent test of the many-electron QED effects on a few percent level in the strongest electromagnetic field presently available in experiments.
  Physical Review Letters 02/2012; 108(7):073001. · 7.37 Impact Factor
• Article: Probing the nuclide W-180 for neutrinoless double-electron capture exploration

  C. Droese, K. Blaum, M. Block, S. Eliseev, F. Herfurth, E. Minaya Ramirez, Yu. Novikov, L. Schweikhard, V.M. Shabaev, I.I. Tupitsyn, S. Wycech, K. Zuber, N.A. Zubova
  Nuclear Physics A 01/2012; · 1.54 Impact Factor
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  Available from: ArXiv

  Article: Evaluation of the screened vacuum-polarization corrections to the hyperfine splitting of Li-like bismuth

  O. V. Andreev, D. A. Glazov, A. V. Volotka, V. M. Shabaev, G. Plunien
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  ABSTRACT: The rigorous calculation of the vacuum-polarization screening corrections to the hyperfine splitting in Li-like bismuth is presented. The two-electron diagrams with electric and magnetic vacuum-polarization loops are evaluated to all orders in alpha*Z, including the Wichmann-Kroll contributions. This improves the accuracy of the theoretical prediction for the specific difference of the hyperfine splitting values of H- and Li-like bismuth.
  12/2011;
• Source

  Available from: Ilya Tupitsyn

  Article: Relativistic calculations of the K-K charge transfer and K-vacancy production probabilities in low-energy ion-atom collisions

  I. I. Tupitsyn, Y. S. Kozhedub, V. M. Shabaev, A. I. Bondarev, G. B. Deyneka, I. A. Maltsev, S. Hagmann, G. Plunien, Th. Stoehlker
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  ABSTRACT: The previously developed technique for evaluation of charge-transfer and electron-excitation processes in low-energy heavy-ion collisions [I.I. Tupitsyn et al., Phys. Rev. A 82, 042701(2010)] is extended to collisions of ions with neutral atoms. The method employs the active electron approximation, in which only the active electron participates in the charge transfer and excitation processes while the passive electrons provide the screening DFT potential. The time-dependent Dirac wave function of the active electron is represented as a linear combination of atomic-like Dirac-Fock-Sturm orbitals, localized at the ions (atoms). The screening DFT potential is calculated using the overlapping densities of each ions (atoms), derived from the atomic orbitals of the passive electrons. The atomic orbitals are generated by solving numerically the one-center Dirac-Fock and Dirac-Fock-Sturm equations by means of a finite-difference approach with the potential taken as the sum of the exact reference ion (atom) Dirac-Fock potential and of the Coulomb potential from the other ion within the monopole approximation. The method developed is used to calculate the K-K charge transfer and K-vacancy production probabilties for the Ne$(1s^2 2s^2 2p^6)$ -- F$^{8+}(1s)$ collisions at the F$^{8+}(1s)$ projectile energies 130 keV/u and 230 keV/u. The obtained results are compared with experimental data and other theoretical calculations. The K-K charge transfer and K-vacancy production probabilities are also calculated for the Xe -- Xe$^{53+}(1s)$ collision.
  12/2011;
• Source

  Available from: Ilya Tupitsyn

  Article: Probing the nuclide 180W for neutrinoless double-electron capture exploration

  C. Droese, K Blaum, M Block, S. Eliseev, F. Herfurth, E. Minaya-Ramirez, Yu N Novikov, L Schweikhard, V. M. Shabaev, I. I. Tupitsyn, S. Wycech, K Zuber, N. A. Zubova
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  ABSTRACT: The mass difference of the nuclides 180W and 180Hf has been measured with the Penning-trap mass spectrometer SHIPTRAP to investigate 180W as a possible candidate for the search for neutrinoless doubleelectron capture. The Q-value was measured to 143.20(27)keV. This value in combination with the calculations of the atomic electron wave functions and other parameters results in a half-life of the 0+ \rightarrow 0+ ground-state to ground-state double-electron capture transition of approximately 5\cdot10E27 years/<m_ee[eV]>^2.
  11/2011;
• Article: Octupolar-excitation Penning-trap mass spectrometry for Q-value measurement of double-electron capture in (164)Er.

  S Eliseev, C Roux, K Blaum, M Block, C Droese, F Herfurth, M Kretzschmar, M I Krivoruchenko, E Minaya Ramirez, Yu N Novikov, L Schweikhard, V M Shabaev, F Simkovic, I I Tupitsyn, K Zuber, N A Zubova
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  ABSTRACT: The theory of octupolar-excitation ion-cyclotron-resonance mass spectrometry is presented which predicts an increase of up to several orders of magnitude in resolving power under certain conditions. The new method has been applied for a direct Penning-trap mass-ratio determination of the (164)Er-(164)Dy mass doublet. (164)Er is a candidate for the search for neutrinoless double-electron capture. However, the measured Q(ϵϵ) value of 25.07(12) keV results in a half-life of 10(30) years for a 1 eV Majorana-neutrino mass.
  Physical Review Letters 10/2011; 107(15):152501. · 7.37 Impact Factor
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  Available from: ArXiv

  Article: Parity nonconservation effect in resonance recombination of polarized electrons with heavy hydrogenlike ions

  A. V. Maiorova, V. M. Shabaev, A. V. Volotka, V. A. Zaytsev, G. Plunien, T. Stoehlker
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  ABSTRACT: Parity nonconservation (PNC) effect in recombination of a polarized electron with a heavy H-like ion in case of resonance with a doubly excited state of the corresponding He-like ion is studied. It is assumed that photons of the energy corresponding to the one-photon decay of the doubly excited state into the $2^1S_0$ or the $2^3P_0$ state are detected at a given angle with respect to the incident electron momentum. Calculations are performed for heliumlike thorium ($Z = 90$) and gadolinium ($Z = 64$), where the $2^1S_0$ and $2^3P_0$ levels are near to cross and, therefore, the PNC effect is strongly enhanced.
  Journal of Physics B Atomic Molecular and Optical Physics 09/2011; 44(22). · 1.88 Impact Factor
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  Available from: ArXiv

  Article: Interelectronic-interaction effects on the two-photon decay rates of heavy He-like ions

  A. V. Volotka, A. Surzhykov, V. M. Shabaev, G. Plunien
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  ABSTRACT: Based on a rigorous QED approach a theoretical analysis is performed for the two-photon transitions in heavy He-like ions. Special attention is paid to the interelectronic-interaction corrections to the decay rates that are taken into account within the two-time Green-function method. Detailed calculations are carried out for the two-photon transitions 2^1S_0 -> 1^1S_0 and 2^3S_1 -> 1^1S_0 in He-like ions within the range of nuclear numbers Z=28-92. The total decay rates together with the spectral distributions are given. The obtained results are compared with experimental values and previous calculations.
  05/2011;
• Article: Quantum Electrodynamics Effects in Heavy Ions and Atoms

  V. M. Shabaev, O. V. Andreev, A. I. Bondarev, D. A. Glazov, Y. S. Kozhedub, A. V. Maiorova, G. Plunien, I. I. Tupitsyn, A. V. Volotka
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  ABSTRACT: Quantum electrodynamics theory of heavy ions and atoms is considered. The current status of calculations of the binding energies, the hyperfine splitting and g factor values in heavy few‐electron ions is reviewed. The theoretical predictions are compared with available experimental data. A special attention is focused on tests of quantum electrodynamics in strong electromagnetic fields and on determination of the fundamental constants. Recent progress in calculations of the parity nonconservation effects with heavy atoms and ions is also reported.
  AIP Conference Proceedings. 05/2011; 1344(1):60-69.
• Article: Resonant Enhancement of Neutrinoless Double-Electron Capture in 152Gd

  Sergey Eliseev, Christian Roux, Klaus Blaum, Michael Block, D. Droese, Frank Herfurth, Hans-Jürgen Kluge, M. I. Krivoruchenko, Yuri N. Novikov, E. Minaya-Ramirez, Lutz Schweikhard, V. M. Shabaev, F. Simkovic, I. I. Tupitsyn, Kai Zuber, N. A. Zubova
  Physical Review Letters 02/2011; 106:052504. · 7.37 Impact Factor
• Article: Resonant enhancement of neutrinoless double-electron capture in 152Gd.

  S Eliseev, C Roux, K Blaum, M Block, C Droese, F Herfurth, H-J Kluge, M I Krivoruchenko, Yu N Novikov, E Minaya Ramirez, L Schweikhard, V M Shabaev, F Simkovic, I I Tupitsyn, K Zuber, N A Zubova
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  ABSTRACT: In the search for the nuclide with the largest probability for neutrinoless double-electron capture, we have determined the Q(ϵϵ) value between the ground states of (152)Gd and (152)Sm by Penning-trap mass-ratio measurements. The new Q(ϵϵ) value of 55.70(18) keV results in a half-life of 10(26)  yr for a 1 eV neutrino mass. With this smallest half-life among known 0νϵϵ transitions, (152)Gd is a promising candidate for the search for neutrinoless double-electron capture.
  Physical Review Letters 02/2011; 106(5):052504. · 7.37 Impact Factor
• Article: Parity-nonconservation effect with the laser-induced 2^{3} S_ {1}–2^{1} S_ {0} transition in heavy heliumlike ions

  V. M. Shabaev, A. V. Volotka, C. Kozhuharov, G. Plunien, Th. Stöhlker
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  ABSTRACT: The parity-nonconservation (PNC) effect on the laser-induced 2 3S1–2 1S0 transition in heavy heliumlike ions is considered. A simple analytical formula for the PNC correction to the cross section is derived for the case, when the opposite-parity 2 1S0 and 2 3P0 states are almost degenerate and, therefore, the PNC effect is strongly enhanced. Numerical results are presented for heliumlike gadolinium and thorium, which seem the most promising candidates for such experiments. In both Gd and Th cases the photon energy required will be anticipated with a high-energy laser built at GSI. Alternatively, it can be gained with ultraviolet lasers utilizing relativistic Doppler tuning at FAIR facilities in Darmstadt.
  Phys. Rev. A. 05/2010; 81(5).
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  Available from: Ilya Tupitsyn

  Article: Relativistic calculations of the charge-transfer probabilities and cross sections for low-energy collisions of H-like ions with bare nuclei

  I. I. Tupitsyn, Y. S. Kozhedub, V. M. Shabaev, G. B. Deyneka, S. Hagmann, C. Kozhuharov, G. Plunien, Th. Stöhlker
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  ABSTRACT: A new method for solving the time-dependent two-center Dirac equation is developed. The time-dependent Dirac wave function is represented as a sum of atomic-like Dirac-Sturm orbitals, localized at the ions. The atomic orbitals are obtained by solving numerically the finite-difference one-center Dirac and Dirac-Sturm equations with the potential which is the sum of the exact reference-nucleus potential and a monopole-approximation potential from the other nucleus. An original procedure to calculate the two-center integrals with these orbitals is proposed. The approach is tested by calculations of the charge transfer and ionization cross sections for the H(1s)--proton collisions at proton energies from 1 keV to 100 keV. The obtained results are compared with related experimental and other theoretical data. To investigate the role of the relativistic effects, the charge transfer cross sections for the Ne^{9+}(1s)--Ne^{10+} (at energies from 0.1 to 10 MeV/u) and U^{91+}(1s)--U^{92+} (at energies from 6 to 10 MeV/u) collisions are calculated in both relativistic and nonrelativistic cases.
  04/2010;
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  Available from: Christophor Kozhuharov

  Article: Parity nonconservation effect with laser-induced 2^3S_1 - 2^1S_0 transition in heavy heliumlike ions

  V. M. Shabaev, A. V. Volotka, C. Kozhuharov, G. Plunien, Th. Stöhlker
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  ABSTRACT: The parity nonconservation (PNC) effect on the laser-induced 2^3S_1 - 2^1S_0 transition in heavy heliumlike ions is considered. A simple analytical formula for the PNC correction to the cross section is derived for the case, when the opposite-parity 2^1S_0 and 2^3P_0 states are almost degenerate and, therefore, the PNC effect is strongly enhanced. Numerical results are presented for heliumlike gadolinium and thorium, which seem most promising candidates for such kind of experiments. In both Gd and Th cases the photon energy required will be anticipated with a high-energy laser built at GSI. Alternatively, it can be gained with ultraviolet lasers utilizing relativistic Doppler tuning at FAIR facilities in Darmstadt. Comment: 19 pages, 1 table, 3 figures
  04/2010;