0000000000291476
AUTHOR
V. M. Shabaev
showing 11 related works from this author
Qvalue and half-life of double-electron capture in184Os
2012
The observation of neutrinoless double-beta transitionswould reveal physics beyond the Standard Model, asit would establish neutrinos to be Majorana particles,which implies a violation of the lepton number conserva-tion. Experiments searching for these transitions have fo-cused on the detection of neutrinoless double-beta decay(0 ) rather than neutrinoless double-electron capture(0). One reason among others is in general the sig-ni cantly shorter half-life of the 0 process. However,in the case of neutrinoless double-electron capture, thetransition is expected to be resonantly enhanced if theinitial and the nal state of the transition are degeneratein energy [1{3].In this work, we inves…
New Nuclear Magnetic Moment of Bi209 : Resolving the Bismuth Hyperfine Puzzle
2018
A recent measurement of the hyperfine splitting in the ground state of Li-like ${^{208}\mathrm{Bi}}^{80+}$ has established a ``hyperfine puzzle''---the experimental result exhibits a $7\ensuremath{\sigma}$ deviation from the theoretical prediction [J. Ullmann et al., Nat. Commun. 8, 15484 (2017); J. P. Karr, Nat. Phys. 13, 533 (2017)]. We provide evidence that the discrepancy is caused by an inaccurate value of the tabulated nuclear magnetic moment (${\ensuremath{\mu}}_{I}$) of $^{209}\mathrm{Bi}$. We perform relativistic density functional theory and relativistic coupled cluster calculations of the shielding constant that should be used to extract the value of ${\ensuremath{\mu}}_{I}(^{209…
Octupolar-Excitation Penning-Trap Mass Spectrometry forQ-Value Measurement of Double-Electron Capture inEr164
2011
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 $^{164}\mathrm{Er}\mathrm{\text{\ensuremath{-}}}^{164}\mathrm{Dy}$ mass doublet. $^{164}\mathrm{Er}$ 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.
Probing the nuclide 180W for neutrinoless double-electron capture exploration
2011
Abstract The mass difference of the nuclides 180 W and 180 Hf has been measured with the Penning-trap mass spectrometer SHIPTRAP to investigate 180 W as a possible candidate for the search for neutrinoless double-electron capture. The Q ϵ ϵ -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 + → 0 + ground-state to ground-state double-electron capture transition of approximately 5 × 10 27 years / 〈 m ϵ ϵ [ eV ] 〉 2 .
Double-βtransformations in isobaric triplets with mass numbersA=124, 130, and 136
2012
The Q values of double-electron capture in ${}^{124}$Xe, ${}^{130}$Ba, and ${}^{136}$Ce and double-beta decay of ${}^{124}$Sn and ${}^{130}$Te have been determined with the Penning-trap mass spectrometer SHIPTRAP with a few hundred eV uncertainty. These nuclides are members of three isobaric triplets with common daughter nuclides. The main goal of this work was to investigate the existence of the resonant enhancement of the neutrinoless double-electron-capture rates in ${}^{124}$Xe and ${}^{130}$Ba in order to assess their suitability for the search for neutrinoless double-electron capture. Based on our results, in neither of these cases is the resonance condition fulfilled.
Resonant enhancement of neutrinoless double-electron capture in 152Gd.
2010
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 $^{152}\mathrm{Gd}$ and $^{152}\mathrm{Sm}$ by Penning-trap mass-ratio measurements. The new ${Q}_{ϵϵ}$ value of 55.70(18) keV results in a half-life of ${10}^{26}\text{ }\text{ }\mathrm{yr}$ for a 1 eV neutrino mass. With this smallest half-life among known $0\ensuremath{\nu}ϵϵ$ transitions, $^{152}\mathrm{Gd}$ is a promising candidate for the search for neutrinoless double-electron capture.
g Factor of Lithiumlike Silicon: New Challenge to Bound-State QED
2019
The recently established agreement between experiment and theory for the $g$ factors of lithiumlike silicon and calcium ions manifests the most stringent test of the many-electron bound-state quantum electrodynamics (QED) effects in the presence of a magnetic field. In this Letter, we present a significant simultaneous improvement of both theoretical $g_\text{th} = 2.000\,889\,894\,4\,(34)$ and experimental $g_\text{exp} = 2.000\,889\,888\,45\,(14)$ values of the $g$ factor of lithiumlike silicon $^{28}$Si$^{11+}$. The theoretical precision now is limited by the many-electron two-loop contributions of the bound-state QED. The experimental value is accurate enough to test these contributions…
New access to the magnetic moment distribution in the nucleus by laser spectroscopy of highly charged ions
1997
Abstract The availability of high intensity, high quality beams of highly charged ions has started a new application for laser spectroscopy. High resolution spectroscopy can now be applied to a study of hydrogen-like atomic states in heavy elements. In principal, this will allow a determination of the hyperfine splitting with an accuracy in the 10 −6 -range or better. Presently this exceeds the limits given by the uncertainties of the nuclear quantities, especially the distribution of the nuclear magnetization in the nucleus. Since the new approach can be applied to a family of test cases, it can provide a wide experimental basis for the separation of nuclear and QED effects. This is especi…
The nuclear magnetic moment of 208Bi and its relevance for a test of bound-state strong-field QED
2018
Physics letters / B 779, 324 - 330 (2018). doi:10.1016/j.physletb.2018.02.024
Isotope dependence of the Zeeman effect in lithium-like calcium
2016
The magnetic moment μ of a bound electron, generally expressed by the g-factor μ=−g μB s ħ−1 with μB the Bohr magneton and s the electron's spin, can be calculated by bound-state quantum electrodynamics (BS-QED) to very high precision. The recent ultra-precise experiment on hydrogen-like silicon determined this value to eleven significant digits, and thus allowed to rigorously probe the validity of BS-QED. Yet, the investigation of one of the most interesting contribution to the g-factor, the relativistic interaction between electron and nucleus, is limited by our knowledge of BS-QED effects. By comparing the g-factors of two isotopes, it is possible to cancel most of these contributions an…
Determination of the electron’s mass from g -factor experiments on 12 C 5+ and 16 O 7+
2003
Abstract We present a derivation of the electron’s mass from our experiment on the electronic g factor in 12C5+ and 16O7+ together with the most recent quantum electrodynamical predictions. The value obtained from 12C5+ is me=0.0005485799093(3) u, that from oxygen is me=0.0005485799092(5) u. Both values agree with the currently accepted one within 1.5 standard deviations but are four respectively two-and-a-half times more precise. The contributions to the uncertainties of our values and perspectives for the determination of the fine-structure constant α by an experiment on the bound-electron g factor are discussed.