4,171 research outputs found

    Hyperfine structure of S-states in muonic deuterium

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    On the basis of quasipotential method in quantum electrodynamics we calculate corrections of order α5\alpha^5 and α6\alpha^6 to hyperfine structure of S-wave energy levels of muonic deuterium. Relativistic corrections, effects of vacuum polarization in first, second and third orders of perturbation theory, nuclear structure and recoil corrections are taken into account. The obtained numerical values of hyperfine splitting ΔEhfs(1S)=50.2814\Delta E^{hfs}(1S)=50.2814 meV (1S state) and ΔEhfs(2S)=6.2804\Delta E^{hfs}(2S)=6.2804 meV (2S state) represent reliable estimate for a comparison with forthcoming experimental data of CREMA collaboration. The hyperfine structure interval Δ12=8ΔEhfs(2S)ΔEhfs(1S)=0.0379\Delta_{12}=8\Delta E^{hfs}(2S)-\Delta E^{hfs}(1S)=-0.0379 meV can be used for precision check of quantum electrodynamics predictions for muonic deterium.Comment: 18 pages, 7 figure

    X-radiation of the moon and Roentgen cosmic background according to data of AMS ''Luna-12''

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    Satellite measurements of lunar soft X radiation, and Roentgen cosmic backgroun

    Radiative nonrecoil nuclear finite size corrections of order α(Zα)5\alpha(Z\alpha)^5 to the hyperfine splitting of S-states in muonic hydrogen

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    On the basis of quasipotential method in quantum electrodynamics we calculate nuclear finite size radiative corrections of order α(Zα)5\alpha(Z\alpha)^5 to the hyperfine structure of S-wave energy levels in muonic hydrogen and muonic deuterium. For the construction of the particle interaction operator we employ the projection operators on the particle bound states with definite spins. The calculation is performed in the infrared safe Fried-Yennie gauge. Modern experimental data on the electromagnetic form factors of the proton and deuteron are used.Comment: 8 pages, 1 figur

    The concept of correlated density and its application

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    The correlated density appears in many physical systems ranging from dense interacting gases up to Fermi liquids which develop a coherent state at low temperatures, the superconductivity. One consequence of the correlated density is the Bernoulli potential in superconductors which compensates forces from dielectric currents. This Bernoulli potential allows to access material parameters. Though within the surface potential these contributions are largely canceled, the bulk measurements with NMR can access this potential. Recent experiments are explained and new ones suggested. The underlying quantum statistical theory in nonequilibrium is the nonlocal kinetic theory developed earlier.Comment: 14 pages, CMT30 proceeding

    Natronoflexus pectinivorans gen. nov. sp. nov., an obligately anaerobic and alkaliphilic fermentative member of Bacteroidetes from soda lakes

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    Anaerobic enrichment with pectin at pH 10 and moderate salinity inoculated with sediments from soda lakes of the Kulunda Steppe (Altai, Russia) resulted in the isolation of a novel member of the Bacteroidetes, strain AP1T. The cells are long, flexible, Gram-negative rods forming pink carotenoids. The isolate is an obligate anaerobe, fermenting various carbohydrates to acetate and succinate. It can hydrolyze and utilize pectin, xylan, starch, laminarin and pullulan as growth substrates. Growth is possible in a pH range from 8 to 10.5, with an optimum at pH 9.5, and at a salinity range from 0.1 to 2 M Na+. Phylogenetic analysis based on 16S rRNA sequences placed the isolate into the phylum Bacteroidetes as a separate lineage within the family Marinilabilaceae. On the basis of distinct phenotype and phylogeny, the soda lake isolate AP1T is proposed to be assigned in a new genus and species Natronoflexus pectinivorans (=DSM24179T = UNIQEM U807T)

    Soliton absorption spectroscopy

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    We analyze optical soliton propagation in the presence of weak absorption lines with much narrower linewidths as compared to the soliton spectrum width using the novel perturbation analysis technique based on an integral representation in the spectral domain. The stable soliton acquires spectral modulation that follows the associated index of refraction of the absorber. The model can be applied to ordinary soliton propagation and to an absorber inside a passively modelocked laser. In the latter case, a comparison with water vapor absorption in a femtosecond Cr:ZnSe laser yields a very good agreement with experiment. Compared to the conventional absorption measurement in a cell of the same length, the signal is increased by an order of magnitude. The obtained analytical expressions allow further improving of the sensitivity and spectroscopic accuracy making the soliton absorption spectroscopy a promising novel measurement technique.Comment: 9 pages, 7 figures
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