Optical Lattice Polarization Effects on Hyperpolarizability of Atomic Clock Transitions

The light-induced frequency shift due to the hyperpolarizability (i.e. terms of second-order in intensity) is studied for a forbidden optical transition, $J$=0$\to$$J$=0. A simple universal dependence on the field ellipticity is obtained. This result allows minimization of the second-order light shift with respect to the field polarization for optical lattices operating at a magic wavelength (at which the first-order shift vanishes). We show the possibility for the existence of a magic elliptical polarization, for which the second-order frequency shift vanishes. The optimal polarization of the lattice field can be either linear, circular or magic elliptical. The obtained results could improve the accuracy of lattice-based atomic clocks.Comment: 4 pages, RevTeX4, 2 eps fig

Ultrastable Optical Clock with Neutral Atoms in an Engineered Light Shift Trap

An ultrastable optical clock based on neutral atoms trapped in an optical lattice is proposed. Complete control over the light shift is achieved by employing the $5s^2 {}^1S_0 \to 5s5p {}^3P_0$ transition of ${}^{87}{\rm Sr}$ atoms as a "clock transition". Calculations of ac multipole polarizabilities and dipole hyperpolarizabilities for the clock transition indicate that the contribution of the higher-order light shifts can be reduced to less than 1 mHz, allowing for a projected accuracy of better than $10^{-17}$.Comment: 4 pages, 2 figures, accepted for publication in Phys. Rev. Let

Trapping of Neutral Mercury Atoms and Prospects for Optical Lattice Clocks

We report a vapor-cell magneto-optical trapping of Hg isotopes on the ${}^1S_0-{}^3P_1$ intercombination transition. Six abundant isotopes, including four bosons and two fermions, were trapped. Hg is the heaviest non-radioactive atom trapped so far, which enables sensitive atomic searches for ``new physics'' beyond the standard model. We propose an accurate optical lattice clock based on Hg and evaluate its systematic accuracy to be better than $10^{-18}$. Highly accurate and stable Hg-based clocks will provide a new avenue for the research of optical lattice clocks and the time variation of the fine-structure constant.Comment: 4 pages, 3 figure

Frequency Light Shifts Caused by the Effects of Quantization of Atomic Motion in an Optical Lattice

Frequency light shifts resulting from the localization effects and effects of the quantization of translational atomic motion in an optical lattice is studied for a forbidden optical transition $J$=0$\to$$J$=0. In the Lamb-Dicke regime this shift is proportional to the square root from the lattice field intensity. With allowance made for magneto-dipole and quadrupole transitions, the shift does not vanish at the magic wavelength, at which the linear in intensity shift is absent. Preliminary estimates show that this shift can have a principal significance for the lattice-based atomic clocks with accuracy of order of 10$^{-16}-10^{-18}$. Apart from this, we find that the numerical value of the magic frequency depends on the concrete configuration of the lattice field and it can vary within the limits 1-100 MHz (depending on element) as one passes from one field configuration to another. Thus, theoretical and experimental investigations of contributions originated from magneto-dipole and quadrupole transitions are of principal self-dependent interest.Comment: 4 pages,1 figure, RevTe

The Development of Nuclear Frequency Standard with the Use of Ion Crystals Manipulation System

AbstractThe perspectives for the increase in the accuracy of optical frequency standards by means of the development of “nuclear clocks” – a novel frequency standard based on the nuclear transition to the long-living isomer nuclear state of thorium-229 with energy ∼7.6eV are discussed. Theoretical estimations give a possible accuracy Δν/ν ∼1×10-20, that allows wide scope of applications for a frequency standard, from satellite navigation systems to experimental verification of the principles of the general theory of relativity. The results are presented and the future prospects for research are discussed on the measurement of the isomeric transition in the nucleus of thorium-229 and creation on its basis the frequency standard of the new generation

Towards a sensitive search for variation of the fine structure constant using radio-frequency E1 transitions in atomic dysprosium

It has been proposed that the radio-frequency electric-dipole (E1) transition between two nearly degenerate opposite-parity states in atomic dysprosium should be highly sensitive to possible temporal variation of the fine structure constant ($\alpha$) [V. A. Dzuba, V. V. Flambaum, and J. K. Webb, Phys. Rev. A {\bf 59}, 230 (1999)]. We analyze here an experimental realization of the proposed search in progress in our laboratory, which involves monitoring the E1 transition frequency over a period of time using direct frequency counting techniques. We estimate that a statistical sensitivity of |\adota| \sim 10^{-18}/yr may be achieved and discuss possible systematic effects that may limit such a measurement.Comment: 8 pages, 7 figure

Radiative Corrections to One-Photon Decays of Hydrogenic Ions

Radiative corrections to the decay rate of n=2 states of hydrogenic ions are calculated. The transitions considered are the M1 decay of the 2s state to the ground state and the E1(M2) decays of the $2p_{1/2}$ and $2p_{3/2}$ states to the ground state. The radiative corrections start in order $\alpha (Z \alpha)^2$, but the method used sums all orders of $Z\alpha$. The leading $\alpha (Z\alpha)^2$ correction for the E1 decays is calculated and compared with the exact result. The extension of the calculational method to parity nonconserving transitions in neutral atoms is discussed.Comment: 22 pages, 2 figure

The Deuterium-to-Hydrogen Ratio in a Low-Metallicity Cloud Falling onto the Milky Way

Using Far Ultraviolet Spectroscopic Explorer and Hubble Space Telescope observations of the QSO PG1259+593, we detect D I Lyman-series absorption in high velocity cloud Complex C, a low-metallicity gas cloud falling onto the Milky Way. This is the first detection of atomic deuterium in the local universe in a location other than the nearby regions of the Galactic disk. A new Westerbork Synthesis Radio Telescope (WSRT) interferometer map of the H I 21 cm emission toward PG1259+593 indicates that the sight line passes through a compact concentration of neutral gas in Complex C. We find D/H = (2.2+/-0.7)x10^-5, O/H = (8.0+/-2.5)x10^-5, and D/O = 0.28+/-0.12. The metallicity of Complex C gas toward PG1259+593 is approximately 1/6 solar, as inferred from the oxygen abundance [O/H] = -0.79 (+0.12, -0.16). While we cannot rule out a value of D/H similar to that found for the local ISM, we can confidently exclude values as low as those determined recently for extended sight lines in the Galactic disk. Combined with the sub-solar metallicity estimate and the low nitrogen abundance, this conclusion lends support to the hypothesis that Complex C is located outside the Milky Way, rather than inside in material recirculated between the Galactic disk and halo. The value of D/H for Complex C is consistent with the primordial abundance of deuterium inferred from recent Wilkinson Microwave Anisotropy Probe observations of the cosmic microwave background and simple chemical evolution models that predict the amount of deuterium astration as a function of metallicity. [Abbreviated abstract]Comment: 77 pages, AASTeX preprint format, includes 17 figures and 11 tables. To be published in the February 2004 Astrophysical Journal Supplement Series (vol. 150, n2

Precision physics of simple atoms: QED tests, nuclear structure and fundamental constants

Quantum electrodynamics is the first successful and still the most successful quantum field theory. Simple atoms, being essentially QED systems, allow highly accurate theoretical predictions. Because of their simple spectra, such atoms have been also efficiently studied experimentally frequently offering the most precisely measured quantities. Our review is devoted to comparison of theory and experiment in the field of precision physics of light simple atoms. In particular, we consider the Lamb shift in the hydrogen atom, the hyperfine structure in hydrogen, deuterium, helium-3 ion, muonium and positronium, as well as a number of other transitions in positronium. Additionally to a spectrum of unperturbed atoms, we consider annihilation decay of positronium and the g factor of bound particles in various two-body atoms. Special attention is paid to the uncertainty of the QED calculations due to the uncalculated higher-order corrections and effects of the nuclear structure. We also discuss applications of simple atoms to determination of several fundamental constants

TECHNICAL MEANS FOR OBTAINING INTERMEDIATE PRODUCTS OF THE CASING AND TOPPINGS FOR EXTRUDED FOOD PRODUCTS

The following article is devoted to the new technical facilities for food production, which technological chain of production process includes computer hardware as a part of the equipment used for body of semi-processed food preparation, blancher for hydrobionts and abrasive blender. For the whole group of the necessary equipment the principal schemes are designed, and the abrasive blender was tested during the experimental approbation to reveal the optimal design. The culinary fish pastes have already been produced in the enterprises in many countries for many years and they are particularly popular in Japan, Germany, Scandinavian and other country. In Poland the mixtures of fish pasted have become widely spread, and are used for production of portioned meals. These pastes may be blended into larger or smaller pieces. The aromatization process of such pastes is conducted with adding the liquid smoke, natural or synthetic fragrances. There is an increasing popularization of the use of flaxseed as a source of alpha-linoleic acid, high-quality protein, phenolics, fiber and minerals. Products with flax meal can be recommended for inclusion in the diet to make up for the deficit of polyunsaturated fatty acids, dietary fiber. In this regard, it is appropriate to use the semi-finished product formulations for the respective housings extruded snack food. The results of the conducted research could be used in the production of domestic extruded snacks, which have the form of the cushions with vitaminized dough body and hydrobionts stuffing if setting the special extrusion modes