Nuclear-spin-dependent parity nonconservation in s-d_5/2 and s-d_3/2 transitions

We perform calculations of s-d_5/2 nuclear-spin-dependent parity nonconservation amplitudes for Rb, Cs, Ba+, Yb+, Fr, Ra+ and Ac++. These systems prove to be good candidates for the use in atomic experiments to extract the so-called anapole moment, a P-odd T-even nuclear moment important for the study of parity violating nuclear forces. We also extend our previous works by calculating the missed spin-dependent amplitudes for the s-d_3/2 transitions in the above systems.Comment: 8 page

Tests of CPT and Lorentz symmetry from muon anomalous magnetic dipole moment

We derive the relativistic factor for splitting of the $g$-factors of a fermion and its anti-fermion partner, which is important for placing constraints on dimension-5, $CPT$-odd and Lorentz-invariance-violating interactions from experiments performed in a cyclotron. From existing data, we extract limits (1$\sigma$) on the coupling strengths of the temporal component, $f^0$, of a background field (including the field amplitude), which is responsible for such $g$-factor splitting, with an electron, proton, and muon: $|f^0_e|< 2.3 \times 10^{-12} ~\mu_{\textrm{B}}$, $|f^0_p|< 4 \times 10^{-9} ~\mu_{\textrm{B}}$, and $|f^0_\mu|< 8 \times 10^{-11} ~\mu_{\textrm{B}}$, respectively, in the laboratory frame. From existing data, we also extract limits on the coupling strengths of the spatial components, $d^{\perp}$, of related dimension-5 interactions of a background field with an electron, proton, neutron, and muon: $| {d}_e^{\perp} | \lesssim 10^{-9} ~\mu_{\textrm{B}}$, $| {d}_p^{\perp} | \lesssim 10^{-9} ~\mu_{\textrm{B}}$, $| {d}_n^{\perp} | \lesssim 10^{-10} ~\mu_{\textrm{B}}$, and $| {d}_\mu^{\perp} | \lesssim 10^{-9} ~\mu_{\textrm{B}}$, respectively, in the laboratory frame.Comment: 6 pages. Minor corrections and new references adde

Quantum electrodynamics corrections to energies, transition amplitudes and parity nonconservation in Rb, Cs, Ba+^+, Tl, Fr and Ra+^+

We use previously developed radiative potential method to calculate quantum electrodynamic (QED) corrections to energy levels and electric dipole transition amplitudes for atoms which are used for the study of the parity non-conservation (PNC) in atoms. The QED shift in energies and dipole amplitudes leads to noticeable change in the PNC amplitudes. This study compliments the previously considered QED corrections to the weak matrix elements. We demonstrate that the QED corrections due to the change in energies and dipole matrix elements are comparable in value to those due to change in weak matrix elements.Comment: 5 pages, 1 figur

Double core polarization contribution to atomic PNC and EDM calculations

We present a detailed study of the effect of the double core polarization (the polarization of the core electrons due to the simultaneous action of the electric dipole and parity-violating weak fields) for amplitudes of the s-s and s-d parity non-conserving transitions in Rb, Cs, Ba +, La 2+, Tl, Fr, Ra +, Ac 2+ and Th 3+ as well as electron EDM enhancement factors for the ground states of the above neutral atoms and Au. This effect is quite large and has the potential to resolve some disagreement between calculations in the literature. It also has significant consequences for the use of experimental data in the accuracy analysis.Comment: 6 page

Dark matter scattering on electrons: Accurate calculations of atomic excitations and implications for the DAMA signal

We revisit the WIMP-type dark matter scattering on electrons that results in atomic ionization, and can manifest itself in a variety of existing direct-detection experiments. Unlike the WIMP-nucleon scattering, where current experiments probe typical interaction strengths much smaller than the Fermi constant, the scattering on electrons requires a much stronger interaction to be detectable, which in turn requires new light force carriers. We account for such new forces explicitly, by introducing a mediator particle with scalar or vector couplings to dark matter and to electrons. We then perform state of the art numerical calculations of atomic ionization relevant to the existing experiments. Our goals are to consistently take into account the atomic physics aspect of the problem (e.g., the relativistic effects, which can be quite significant), and to scan the parameter space: the dark matter mass, the mediator mass, and the effective coupling strength, to see if there is any part of the parameter space that could potentially explain the DAMA modulation signal. While we find that the modulation fraction of all events with energy deposition above 2 keV in NaI can be quite significant, reaching ~50%, the relevant parts of the parameter space are excluded by the XENON10 and XENON100 experiments

Development of a 100 watt S-band traveling- wave tube Quarterly progress report

Development of 100 watt S band traveling wave tube for space application