39 research outputs found
Nuclear polarization in heavy atoms and superheavy quasiatoms
We consider the contribution of nuclear polarization to the Lamb shift of K- and L-shell electrons in heavy atoms and quasiatoms. Our formal approach is based on the concept of effective photon propagators with nuclear-polarization insertions treating effects of nuclear polarization on the same footing as usual QED radiative corrections. We explicitly derive the modification of the photon propagator for various collective nuclear excitations and calculate the corresponding effective self-energy shift perturbatively. The energy shift of the 1s1/2 state in 92238U due to virtual excitation of nuclear rotational states is shown to be a considerable correction for atomic high-precision experiments. In contrast to this, nuclear-polarization effects are of minor importance for Lamb-shift studies in 82208Pb
Nuclear polarization contribution to the Lamb shift in heavy atoms
The energy shift of the 1s1/2 state in 92238U due to virtual excitation of nuclear rotational modes is shown to be a considerable correction for atomic high-precision experiments. In contrast to this, nuclear polarization effects are of minor importance for Lamb-shift studies in 82208Pb
g factor of lithiumlike silicon 28Si11+
The g factor of lithiumlike 28Si11+ has been measured in a triple-Penning
trap with a relative uncertainty of 1.1x10^{-9} to be g_exp=2.0008898899(21).
The theoretical prediction for this value was calculated to be
g_th=2.000889909(51) improving the accuracy to 2.5x10^{-8} due to the first
rigorous evaluation of the two-photon exchange correction. The measured value
is in excellent agreement with the state-of-the-art theoretical prediction and
yields the most stringent test of bound-state QED for the g factor of the
1s^22s state and the relativistic many-electron calculations in a magnetic
field
Dynamical Casimir Effect in a Designed Leaky Cavity
The phenomenon of particle creation within a resonantly vibrating lossy
cavity is investigated for the example of a massless scalar field at finite
temperature. Leakage is provided by insertion of a dispersive mirror into a
larger ideal cavity. Via the rotating wave approximation we demonstrate that
for the case of parametric resonance the exponential growth of the number of
created particles and the strong enhancement at finite temperatures are
preserved in the presence of reasonable losses. The relevance for experimental
tests of quantum radiation via the dynamical Casimir effect is addressed.Comment: 1 figur
Resonant cavity photon creation via the dynamical Casimir effect
Motivated by a recent proposal for an experimental verification of the
dynamical Casimir effect, the macroscopic electromagnetic field within a
perfect cavity containing a thin slab with a time-dependent dielectric
permittivity is quantized in terms of the dual potentials. For the resonance
case, the number of photons created out of the vacuum due to the dynamical
Casimir effect is calculated for both polarizations (TE and TM). PACS:
42.50.Lc, 03.70.+k, 42.50.Dv, 42.60.Da.Comment: 4 pages, 1 figur
Dynamical Casimir effect at finite temperature
Thermal effects on the creation of particles under the influence of
time-dependent boundary conditions are investigated. The dominant temperature
correction to the energy radiated by a moving mirror is derived by means of
response theory. For a resonantly vibrating cavity the thermal effect on the
number of created photons is obtained non-perturbatively. Finite temperatures
can enhance the pure vacuum effect by several orders of magnitude. The
relevance of finite temperature effects for the experimental verification of
the dynamical Casimir effect is addressed.Comment: 9 LaTex page