共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
S. G. Karshenboim V. G. Ivanov E. Yu. Korzinin 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,39(3):351-358
In muonic atoms the Uehling potential (an effect of a
free electronic vacuum polarization loop) is responsible for the
leading contribution to the Lamb shift causing the splitting of
states with Δn=0 and Δl≠0. Here we consider the
Lamb shift in the leading nonrelativistic approximation, i.e.,
within an approach based on a certain Schr?dinger equation. That
is valid for low and medium Z as long as (Zα)2≪1. The
result is a function of a few parameters, including
κ=Zαmμ/me, n and l. We present various
asymptotics and in particular we study a region of validity of
asymptotics with large and small κ. Special attention is
paid to circular states, which are considered in a limit of
n≫1. 相似文献
3.
S. Zschocke G. Plunien G. Soff 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,19(2):147-156
The renormalization method of Bogoljubov-Parasiuk-Hepp-Zimmermann (BPHZ) is used in order to derive the renormalized energy
shift due to the gauge invariant K?llén-Sabry diagram of the two-photon vacuum polarization (VPVP) as well as the self energy
vacuum polarization S(VP)E beyond the Uehling approximation. It is outlined, that no outer renormalization is required for
the two-photon vacuum polarization and that only the inner renormalization has to be accomplished. It is shown that the so-called
nongauge invariant spurious term is absent for a wide class of vacuum polarization (VP) diagrams if one applies the widely
used spherical expansion of bound and free-electron propagator. This simplifies significantly calculations in bound state
quantum electrodynamics. As one result of our paper the use of the BPHZ-approach in bound state QED is established.
Received 28 September 2001 相似文献
4.
T. Beier H. Häffner N. Hermanspahn S. Djekic H.-J. Kluge W. Quint S. Stahl T. Valenzuela J. Verdú G. Werth 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):41-44
We describe a double-Penning-trap experiment suitable for testing QED in strong fields by determining the electronic g-factor of a single hydrogen-like ion in its ground state. Our measurements on 12C5 + reach a relative accuracy of 2×10-9, where the largest uncertainty results from the mass of the electron. Together with equally precise theoretical predictions
therefore, it is possible to evaluate a new value for the electron's mass. The possibilities to obtain other fundamental constants
and nuclear parameters are lined out.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: t.beier@gsi.de 相似文献
5.
A.V. Volotka V.M. Shabaev G. Plunien G. Soff 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(1):51-56
The finite nuclear size effect on the hyperfine splitting of low-Z hydrogen-like atoms is studied in the external field approximation. A simple non-relativistic formula is proposed which expresses
the nuclear size correction to the hyperfine splitting in terms of moments of the nuclear charge and magnetization distribution.
The numerical results obtained via this formula are compared with corresponding results derived by means of the Zemach formula. A relativistic formula for the
nuclear size correction to the hyperfine splitting is also derived.
Received 18 March 2002 / Received in final form 14 November 2002 Published online 28 January 2003
RID="a"
ID="a"e-mail: plunien@physik.tu-dresden.de 相似文献
6.
S. Karshenboim U. Jentschura V. Ivanov G. Soff 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,2(3):209-215
We present an analytical evaluation of radiative corrections in exotic atoms induced by the one-loop electronic vacuum polarization.
We evaluate corrections to the energy levels, to the wave function (at the origin) and to the hyperfine structure. We treat
all corrections analytically within a non-relativistic approximation. Agreement is found with a few available numerical results.
The analytical treatment allows to determine the asymptotic forms of the corrections in the limit of a small atomic radius,
which for the atomic systems considered corresponds to a large mass of the constituent particle as compared to the electron
mass. The asymptotics can be verified using the effective charge approach.
Received: 28 January 1998 / Accepted: 13 March 1998 相似文献
7.
S. G. Karshenboim V. G. Ivanov 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,19(1):13-23
We consider hyperfine splitting of 1s and, in part, of 2s levels in light hydrogen-like atoms: hydrogen, deuterium, tritium, helium-3 ion, muonium and positronium. We discuss present
status of precision theory and experiment for the hfs intervals. We pay a special attention to a specific difference, D
21 = 8E
hfs(2s) - E
hfs(1s), which is known experimentally for hydrogen, deuterium and 3
He
+ ion. The difference is weakly affected by the effects of the nuclear structure and thus may be calculated with a high accuracy.
We complete a calculation of the fourth order QED contributions to this difference and present here new results on corrections due to the nuclear effects. Our theoretical
predictions appear to be in a fair agreement with available experimental data. Comparison of the experimental data with our
examination of D21 allows to test the state-dependent sector of theory of the hfs separation of the 1s and 2s levels in the light hydrogen-like atoms up to 10-8.
Received 22 September 2001 相似文献
8.
S. Varga K. Bolton H. Grönbeck A. Snis A. Rosén B. Fricke 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,16(1):29-32
We present recent theoretical results for the V3 and Au4 clusters. Calculations of the V3 doublet system indicate that the 6-311+G(d) basis set is sufficiently flexible to provide reliable minimum energy structures
and vibrational frequencies, that these structures and frequencies are insensitive to spin contamination of the wave function
when the BPW91 functional is used, and that changing to the B3LYP functional may result in very different structures and frequencies.
A computationally less expensive scalar relativistic treatment of Au4 clusters gives structural properties that are in good agreement with those obtained using a four-component method.
Received 30 November 2000 相似文献
9.
Z.-C. Yan 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,18(1):15-18
The fully correlated calculations of the Zeeman gJ factors for the first three quartet S states of lithium are presented, including relativistic and radiative corrections of
orders α2, α2
m/M, and α3. The isotope shifts in gJ are predicted precisely for various isotopes of lithium.
Received 4 December 2000 and Received in final form 26 September 2001 相似文献
10.
G. Plunien T. Beier Gerhard Soff H. Persson 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,1(2):177-185
We present a calculation scheme for the two-loop vacuum polarization correction of order to the Lamb shift of hydrogenlike high-Z atoms. The interaction with the external Coulomb field is taken into account to all orders in . By means of a modified potential approach the problem is reduced to the evaluation of effective one-loop vacuum polarization
potentials. An expression for the energy shift is deduced within the framework of partial wave decomposition performing appropriate
subtractions. Exact results for the two-loop vacuum polarization contribution to the Lamb shift of K- and L-shell electron
states in hydrogenlike Lead and Uranium are presented.
Received: 10 August 1997 / Revised: 31 October 1997 / Accepted: 18 November 1997 相似文献
11.
V. V. Bondarchuk I. M. Shvab 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,42(3):381-386
With the help of perturbation theory the asymptotic
expansions (at small and large internuclear distances R) of the
eigenvalues (potential curves) E(R) of the two-Coulomb-centre
problem in 2+1 dimensions are obtained. We compare the results
obtained with the data from similar approximation for
two-Coulomb-centre problem in 3+1 dimensions. 相似文献
12.
A. V. Volotka D. A. Glazov G. Plunien V. M. Shabaev I. I. Tupitsyn 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,38(2):293-298
The one-electron quantum-electrodynamic corrections to the
magnetic-dipole transition amplitude
between the fine-structure
levels (1s2 2s2 2p) 2P3/2 - 2P1/2 in boronlike ions
are calculated to all orders in αZ. The results obtained
serve for improving the theoretical accuracy of the lifetime of the
(1s2 2s2 2p) 2P3/2 level in boronlike argon. 相似文献
13.
A. Borschevsky E. Eliav M. J. Vilkas Y. Ishikawa U. Kaldor 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(1):115-119
Transition energies of the superheavy element lawrencium, including the ionization potential, excitation energies and electron
affinities, are calculated by the intermediate Hamiltonian coupled cluster method. A large basis set (37s31p26d21f16g11h6i)
is used, as well as an extensive P space (6s5p4d2f1g). The outer 43 electrons are correlated. Accuracy is monitored by applying
the same approach to lutetium, the lighter homologue of Lr, and comparing with experimentally known energies. QED corrections
are
included. The main goal is to predict excitation energies, in anticipation of planned spectroscopy of Lr.
The ground state of Lr is
, unlike the
of Lu. Predicted Lr excitations with large transition moments in the prime range for the planned experiment, 20 000–30 000 cm-1, are 7p→8s at 20 100 cm-1
and 7p→7d at 28 100 cm-1. The average absolute
error of 20 excitation energies of Lu is 423 cm -1, and the error limits for Lr are put at 700 cm-1.
The two electron affinities measured recently for Lu are reproduced within 55 cm-1, and a third bound state of Lu- is predicted. 相似文献
14.
F. Le Blanc L. Cabaret J.E. Crawford S. Essabaa V. Fedoseyev W. Geithner J. Genevey M. Girod R. Horn G. Huber S. Kappertz J. Lassen J.K.P. Lee G. Le Scornet V. Mishin R. Neugart J. Obert J. Oms A. Ouchrif S. Peru J. Pinard H. Ravn B. Roussière J. Sauvage D. Verney 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):49-51
Laser spectroscopy measurements have been carried out on the very neutron-rich tin isotopes with the COMPLIS experimental
setup. Using the 5s
25p
23
P
0 → 5s
25p6s
3
P
1 optical transition, hyperfine spectra of 126-132Sn and 125m, 127m, 129m-131mSn where recorded for the first time. The variation of the mean-square charge radius ( δ〈r
2〉) between these nuclei and nuclear moments of the isomers and the odd isotopes were thus measured. An odd-even staggering
which inverts at A = 130 is clearly observed. This indicates a small appearance of a plateau on the δ〈r
2〉 which has to be confirmed by measuring the isotope shift beyond A = 132.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: leblanc@ipno.in2p3.fr 相似文献
15.
J.P. Santos F. Parente P. Indelicato 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,3(1):43-52
A theoretical study of the one- and two-photon spontaneous emission rates from the 2
s1/2 state of one-electron ions is presented. High-precision values of the relativistic emission rates for ions with nuclear charge
Z up to 100 are obtained through the use of finite basis sets for the Dirac equation constructed from B-splines. Furthermore,
we analyze the influence of the inclusion of quantum electrodynamics corrections in the initial and final state energies.
Received: 6 January 1998 / Accepted: 31 March 1998 相似文献
16.
We present an analysis of the Raman interaction between a Rydberg atom and ultrashort light pulses. An application of the synchronization of quantum transitions to a simple atomic system (the hydrogen atom) is demonstrated. This is a direct way of measuring times and frequencies of microwave transitions between the high-lying atomic states using ultrashort light pulses. The results and analysis represent a new method for measuring the Rydberg constant. 相似文献
17.
J. P. Marques F. Parente P. Indelicato 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(3):457-465
In this paper, we used the multiconfiguration Dirac-Fock method to compute with high precision the influence of the hyperfine
interaction on the [Ar]
P0 level lifetime in Zn-like ions for stable and some quasi-stable isotopes of nonzero nuclear spin between Z=30 and Z=92. The
influence of this interaction on the
[Ar]
P
P0 separation energy is also calculated for the same ions. 相似文献
18.
A. Surzhykov U. D. Jentschura T. Stöhlker S. Fritzsche 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(1):27-36
We apply the density matrix theory to re-investigate the radiative
electron capture into heavy ions with one valence electron. Attention
has been paid particularly to the magnetic sublevel population of the
residual ions, as described in terms of alignment parameters. Simple
method, based on an independent particle model, which takes
into account the Pauli principle, is proposed for evaluating the
alignment of the excited ionic states. By making use of this method,
detailed calculations are performed for electron capture into (initially) hydrogen-like and lithium-like europium, gold and
uranium ions, and are compared with the results of the multiconfiguration Dirac-Fock approach.As seen from the calculations
and from the comparison with available experimental results, the independent particle model provides a good estimate for the
alignment parameters of few-electron heavy ions. Therefore, our simple model may help to understand the basic properties of
the X-ray emission from heavy, few-electron ions without the need for invoking sophisticated MCDF calculations. 相似文献
19.
F.X. Gadéa T. Leininger A.S. Dickinson 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,15(2):251-255
An improved ab initio calculation has been performed for the potential for the LiH a 3Σ+ state, using two very large basis sets. The Basis Set Superposition Error (BSSE) correction has been determined for both
basis sets and the non-Born-Oppenheimer correction estimated to be negligible. The best potential is approximately 10% deeper
than the previous estimate. Vibrational energies and scattering lengths have been calculated for 6,7LiH(D) with both potentials, with and without the BSSE correction, and also with an estimated potential expected to bracket
the true potential. The 7LiH scattering length is estimated to be (45 ± 4)a0 and hence the low-energy cross-section in the best a 3Σ+ potential is about half that calculated previously. Enhanced cooling by 7Li of trapped H atoms remains feasible.
Received 30 April 2001 相似文献
20.
P. Indelicato S. Boucard E. Lindroth 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,3(1):29-41
We report on a calculation of K, L and M inner-shell ionization energy in atoms with atomic numbers in the range . Many-body effects are evaluated for all n
=1, 2, and 3 hole states. Those include correlation and effects due to the auto-ionizing nature of the hole states (Auger shift). For
high Z we add recent corrected nuclear polarization, and several second-order vacuum polarization corrections. K and L ionization
energies are compared with experimental X-ray absorption edges measurements. Excellent agreement with rare gazes and metal
vapor measurements is found. We also compare our calculations with X-ray transition energies for all K and L lines that involve
K, L and M holes. Finally we use K X-ray lines to deduce an hydrogenlike 1
s Lamb shift for several heavy elements, with far better accuracy than has been obtained by direct measurements of hydrogenlike
ions.
Received: 25 February 1998 / Accepted: 31 March 1998 相似文献