3,072 research outputs found

    Vibrational spectroscopy of H2+: precise evaluation of the Zeeman effect

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    We present an accurate computation of the g-factors of the hyperfine states of the hydrogen molecular ion H2+. The results are in good agreement with previous experiments, and can be tested further by rf spectroscopy. Their implication for high-precision two-photon vibrational spectroscopy of H2+ is also discussed. It is found that the most intense hyperfine components of two-photon lines benefit from a very small Zeeman splitting

    Superconducting gyroscope research

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    Four basic areas of research and development of superconducting gyroscopes are studied. Chapter 1 studies the analysis of a SQUID readout for a superconducting gyroscope. Chapter 2 studies the dependence of spin-up torque on channel and gas properties. Chapter 3 studies the theory of super fluid plug operation. And chapter 4 studies the gyro rotor and housing manufacture

    Theoretical transition frequencies beyond 0.1 ppb accuracy in H2+_2^+, HD+^+, and antiprotonic helium

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    We present improved theoretical calculations of transition frequencies for the fundamental transitions (L ⁣= ⁣0,v ⁣= ⁣1)→(Lâ€Č ⁣= ⁣0,vâ€Č ⁣= ⁣0)(L\!=\!0,v\!=\!1)\to(L'\!=\!0,v'\!=\!0) in the hydrogen molecular ions H2+_2^+ and HD+^+ with a relative uncertainty 4⋅10−114\cdot10^{-11} and for the two-photon transitions in the antiprotonic helium atom with a relative uncertainty 10−1010^{-10}. To do that, the one-loop self-energy correction of order α(Zα)6\alpha(Z\alpha)^6 is derived in the two Coulomb center approximation, and numerically evaluated in the case of the aforementioned transitions. The final results also include a complete set of other spin-independent corrections of order mα7m\alpha^7. The leading order corrections of α2ln⁥3(Zα)−2(Zα)6\alpha^2\ln^3(Z\alpha)^{-2}(Z\alpha)^6 are also considered that allows to estimate a magnitude of yet uncalculated contributions.Comment: 10 pages, 2 figure, to be submitted to PR

    One-loop vacuum polarization at mα7m\alpha^7 order for the two center problem

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    We present calculations of the one-loop vacuum polarization contribution (Uehling potential) for the two-center problem in the NRQED formalism. The cases of hydrogen molecular ions (Z1=Z2=1Z_1=Z_2=1) as well as antiprotonic helium (Z1=2Z_1=2, Z2=−1Z_2=-1) are considered. Numerical results of the vacuum polarization contribution at mα7m\alpha^7 order for the fundamental transitions (v=0,L=0)→(vâ€Č=1,Lâ€Č=0)(v=0,L=0)\to(v'=1,L'=0) in H2+_2^+ and HD+^+ are presented.Comment: 6 pages, 2 figues, submitted to PR

    High accuracy results for the energy levels of the molecular ions H2+, D2+ and HD+, up to J=2

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    We present a nonrelativistic calculation of the rotation-vibration levels of the molecular ions H2+, D2+ and HD+, relying on the diagonalization of the exact three-body Hamiltonian. The J=2 levels are obtained with a very high accuracy of 10^{-14} a.u. (for most levels) representing an improvement by five orders of magnitude over previous calculations. The accuracy is also improved for the J=1 levels of H2+ and D2+ with respect to earlier works. Moreover, we have computed the sensitivities of the energy levels with respect to the mass ratios, allowing these levels to be used for metrological purposes.Comment: 11 page

    Infrared telescope

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    The development of the Infrared Telescope for Spacelab 2 is discussed. The design, development, and testing required to interface a stationary superfluid helium dewar with a scanning cryostate capable of operating in the zero-g environment in the space shuttle bay is described

    Hydrogen molecular ions for improved determination of fundamental constants

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    The possible use of high-resolution rovibrational spectroscopy of the hydrogen molecular ions H + 2 and HD + for an independent determination of several fundamental constants is analyzed. While these molecules had been proposed for metrology of nuclear-to-electron mass ratios, we show that they are also sensitive to the radii of the proton and deuteron and to the Rydberg constant at the level of the current discrepancies colloquially known as the proton size puzzle. The required level of accuracy, in the 10 --12 range, can be reached both by experiments, using Doppler-free two-photon spectroscopy schemes, and by theoretical predictions. It is shown how the measurement of several well-chosen rovibrational transitions may shed new light on the proton-radius puzzle, provide an alternative accurate determination of the Rydberg constant, and yield new values of the proton-to-electron and deuteron-to-proton mass ratios with one order of magnitude higher precision

    Development of a New Test Specimen with Tapered Cross-Section for Use in Uniaxial Fatigue Testing of Hot Mix Asphalt.

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    M.S. Thesis. University of Hawaiʻi at Mānoa 2018

    How to Write a Love Poem

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