Related papers: Calculation of Radiative Corrections to E1 matrix …
We investigate the finite nuclear mass corrections in the helium atom in order to resolve a significant disagreement between the $2^3S - 2^3P$ and $2^3S - 2^1S$ transition isotope shifts. These two transitions lead to discrepant results for…
We calculate isotope mass shift for several light ions using Dirac wave functions and mass shift operator with relativistic corrections of the order of $(\alpha Z)^2$. Calculated relativistic corrections to the specific mass shift vary from…
We estimate the isospin-violating QED radiative corrections to the charged-to-neutral ratios of the decay rates for B^+ and B^0 in non-leptonic B meson decays. In particular, these corrections are potentially important for precision…
Recent high-precision measurements of atomic parity-nonconserving transitions between the 6S and 7S states of cesium allow for a determination of the weak nuclear charge with a precision of 1.3%, providing an improved test of the standard…
Nonrelativistically forbidden, single-photon transition rates between low lying states of the helium atom are rigorously derived within quantum electrodynamics theory. Equivalence of velocity and length gauges, including relativistic…
We report a measurement of the ratio of electric dipole transition matrix elements of cesium for the $6p\,^2P_{1/2} \rightarrow 7s\,^2S_{1/2}$ and $6p\,^2P_{3/2} \rightarrow 7s\,^2S_{1/2}$ transitions. We determine this ratio of matrix…
Hyperfine intervals in light hydrogenic atoms and ions are among the most accurately measured quantities in physics. The theory of QED corrections has recently advanced to the point that uncalculated terms for hydrogenic atoms and ions are…
We have calculated the 6s-7s parity nonconserving (PNC) E1 transition amplitude, E_{PNC}, in cesium. We have used an improved all-order technique in the calculation of the correlations and have included all significant contributions to…
We perform ab initio calculations of isotope shifts for isotopes of cesium (from A=123 to A=137) and francium (from A=207 to A=228). These calculations start from the relativistic Hartree-Fock method and make use of several techniques to…
We have calculated the O(alpha) radiative corrections to the tau decay tau -> pi (K) nu, taking into account both the point meson contribution and the structure dependent radiation. We find for the ratio Gamma(tau -> pi nu (gamma)) /…
We calculate radiative corrections to the flavor-changing neutral current process K --> pi l+ l-, both for charged and neutral kaon decays. While the soft-photon approximation is shown to work well for the muon channels, we discuss the…
This contribution contains the first numerical computation of the complete set of relativistic corrections of relative order $v^{2}$ for electric dipole (E1) transitions in heavy quarkonium; in particular, for the processes $\chi_{bJ}(1P)…
Relativistic calculations of the isotope shifts of energy levels in highly charged Li-like ions are performed. The nuclear recoil (mass shift) contributions are calculated by merging the perturbative and large-scale…
Relativistic exchange current corrections to neutrino--nucleus cross sections are presented assuming non--vanishing strange quark form factors for the constituent nucleons. For charged current processes the exchange current corrections can…
For the low-energy anti-neutrino reaction, $\bar{\nu}_e + p \to e^+ + n$, which is of great current interest in connection with on-going high-precision neutrino-oscillation experiments, we calculate the differential cross section in a…
We have examined modifications to the nuclear weak charge due to small differences between the spatial distributions of neutrons and protons in the Cs nucleus. We derive approximate formulae to estimate the value and uncertainty of this…
We report a new calculation of the parity non-conserving E1 amplitude for the 6p_{1/2} -> 6p_{3/2} transition in Tl. Our result for the reduced matrix element is $E1_{PNC}=-(66.7 \pm 1.7) i 10^{-11} (-Q_W/N)$ a.u. Comparison with the…
Extensive calculations of the electric-dipole matrix elements in alkali-metal atoms are conducted using the relativistic all-order method. This approach is a linearized version of the coupled-cluster method, which sums infinite sets of…
We present a new computation of S-wave color-singlet nonrelativistic QCD matrix elements for the J/psi and the eta_c. We compute the matrix elements of leading order in the heavy-quark velocity v and the matrix elements of relative order…
The theory of QED corrections to hyperfine structure in light hydrogenic atoms and ions has recently advanced to the point that the uncertainty of these corrections is much smaller than 1 part per million (ppm), while the experiments are…