2,181 research outputs found
Measurement of the 6S-7S transition polarizablility in atomic cesium and an improved test of the standard model
The ratio of the off-diagonal hyperfine amplitude to the tensor transition
polarizability (Mhf/beta) for the 6S-7S transition in cesium has been measured.
The value of beta=27.024(43)(expt)(67)(theory)a_0^3 is then obtained using an
accurate semi-empirical value of Mhf. This is combined with a previous
measurement of parity nonconservation in atomic cesium and previous atomic
structure calculations to determine the value of the weak charge. The
uncertainties in the atomic structure calculations are updated (and reduced) in
light of new experimental tests. The result Q_W=-72.06(28)(expt) (34)(theory)
differs from the prediction of the standard model of elementary particle
physics by 2.5 sigma.Comment: 12 pages, 1 figur
Two-loop self-energy correction in high-Z hydrogen-like ions
A complete evaluation of the two-loop self-energy diagrams to all orders in
Z\alpha is presented for the ground state of H-like ions with Z\ge 40.Comment: RevTeX, 5 figures, 1 tabl
An analytically solvable model of the effect of magnetic breakdown on angle-dependent magnetoresistance in a quasi-two-dimensional metal
We have developed an analytical model of angle-dependent magnetoresistance
oscillations (AMROs) in a quasi-two-dimensional metal in which magnetic
breakdown occurs. The model takes account of all the contributions from
quasiparticles undergoing both magnetic breakdown and Bragg reflection at each
junction and allows extremely efficient simulation of data which can be
compared with recent experimental results on the organic metal
kappa-ET2Cu(NCS)2. AMROs resulting from both closed and open orbits emerge
naturally at low field, and the model enables the transition to breakdown-AMROs
with increasing field to be described in detail.Comment: 4 pages, 3 figure
One-loop self-energy correction to the 1s and 2s hyperfine splitting in H-like systems
The one-loop self-energy correction to the hyperfine splitting of the 1s and
2s levels in H-like low-Z atoms is evaluated to all orders in Z\alpha. The
results are compared to perturbative calculations. The residual higher-order
contribution is evaluated. Implications to the specific difference of the
hyperfine structure intervals 8\Delta \nu_2 - \Delta \nu_1 in He^+ are
investigated.Comment: 17 pages, RevTeX, 3 figure
Breit interaction correction to the hyperfine constant of an external s-electron in many-electron atom
Correction to the hyperfine constant of an external s-electron in
many-electron atom caused by the Breit interaction is calculated analytically:
. Physical mechanism for this correction is
polarization of the internal electronic shells (mainly shell) by the
magnetic field of the external electron. This mechanism is similar to the
polarization of vacuum considered by Karplus and Klein long time ago. The
similarity is the reason why in both cases (Dirac sea polarization and internal
atomic shells polarization) the corrections have the same dependence on the
nuclear charge and fine structure constant.
In conclusion we also discuss corrections to the parity violation
effects in atoms.Comment: 8 pages, 2 figure
Collective models of labor supply with nonconvex budget sets and nonparticipation: A calibration approach.
Does the representation of household behavior matter for welfare analysis of tax-benefit policies? An introduction.
Transition energy and lifetime for the ground state hyperfine splitting of high Z lithiumlike ions
The ground state hyperfine splitting values and the transition probabilities
between the hyperfine structure components of high Z lithiumlike ions are
calculated in the range . The relativistic, nuclear, QED and
interelectronic interaction corrections are taken into account. It is found
that the Bohr-Weisskopf effect can be eliminated in a combination of the
hyperfine splitting values of the hydrogenlike and lithiumlike ions of an
isotope. This gives a possibility for testing the QED effects in a combination
of the strong electric and magnetic fields of the heavy nucleus. Using the
experimental result for the hyperfine splitting in ^{209}Bi^{82+}, the 2s
hyperfine splitting in ^{209}Bi^{80+} is calculated to be \Delta E=0.7969(2)
eV.Comment: The nuclear charge distribution correction \delta is corrected, 14
pages, Late
High accuracy calculation of 6s -> 7s parity nonconserving amplitude in Cs
We calculated the parity nonconserving (PNC) 6s -> 7s amplitude in Cs. In the
Dirac-Coulomb approximation our result is in a good agreement with other
calculations. Breit corrections to the PNC amplitude and to the Stark-induced
amplitude are found to be -0.4% and -1% respectively. The weak charge
of Cs is in agreement with the standard model.Comment: 4 pages, LaTeX2e, uses revtex4.cls, submitted to PR
- …