2,026,187 research outputs found

    Daemons and DAMA: Their Celestial-Mechanics Interrelations

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    The assumption of the capture by the Solar System of the electrically charged Planckian DM objects (daemons) from the galactic disk is confirmed not only by the St.Petersburg (SPb) experiments detecting particles with V<30 km/s. Here the daemon approach is analyzed considering the positive model independent result of the DAMA/NaI experiment. We explain the maximum in DAMA signals observed in the May-June period to be associated with the formation behind the Sun of a trail of daemons that the Sun captures into elongated orbits as it moves to the apex. The range of significant 2-6-keV DAMA signals fits well the iodine nuclei elastically knocked out of the NaI(Tl) scintillator by particles falling on the Earth with V=30-50 km/s from strongly elongated heliocentric orbits. The half-year periodicity of the slower daemons observed in SPb originates from the transfer of particles that are deflected through ~90 deg into near-Earth orbits each time the particles cross the outer reaches of the Sun which had captured them. Their multi-loop (cross-like) trajectories traverse many times the Earth's orbit in March and September, which increases the probability for the particles to enter near-Earth orbits during this time. Corroboration of celestial mechanics calculations with observations yields ~1e-19 cm2 for the cross section of daemon interaction with the solar matter.Comment: 12 pages including 5 figure

    NASA/DOD earth orbit shuttle traffic models based on end to end loading of payloads

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    An analysis of the spacecraft configurations and space missions for the Earth Orbit Shuttle traffic model based on an end-to-end loading of payloads is presented. Two possible reusable tugs are considered. The space missions are described with respect to the following: (1) number of earth orbit shuttle flights by inclination, (2) total payloads to orbit, (3) energy stages required, and (4) characteristics of reusable tug

    Orbital order, stacking defects and spin-fluctuations in the pp-electron molecular solid RbO2_2

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    We examine magnon and orbiton behavior in localized O2_2 anti-bonding molecular π\pi^* orbitals using an effective Kugel-Khomskii Hamiltonian derived from a two band Hubbard model with hopping parameters taken from {\em ab initio} density functional calculations. The considerable difference between intraband and interband hoppings leads to a strong coupling between the spin wave dispersion and the orbital ground state, providing a straightforward way of experimentally determining the orbital ground state from the measured magnon dispersion. The near degeneracy of different orbital ordered states leads to stacking defects which further modulate spin-fluctuation spectra. Proliferation of orbital domains disrupts long-range magnetic order, thus causing a significant reduction in the observed N\'eel temperature.Comment: 5 pages, 2 figure

    A Physical Axiomatic Approach to Schrodinger's Equation

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    The Schrodinger equation for non-relativistic quantum systems is derived from some classical physics axioms within an ensemble hamiltonian framework. Such an approach enables one to understand the structure of the equation, in particular its linearity, in intuitive terms. Furthermore it allows for a physically motivated and systematic investigation of potential generalisations which are briefly discussed.Comment: Extended version. 14 page

    Stark deceleration of lithium hydride molecules

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    We describe the production of cold, slow-moving LiH molecules. The molecules are produced in the ground state using laser ablation and supersonic expansion, and 68% of the population is transferred to the rotationally excited state using narrowband radiation at the rotational frequency of 444GHz. The molecules are then decelerated from 420m/s to 53m/s using a 100 stage Stark decelerator. We demonstrate and compare two different deceleration modes, one where every stage is used for deceleration, and another where every third stage decelerates and the intervening stages are used to focus the molecules more effectively. We compare our experimental data to the results of simulations and find good agreement. These simulations include the velocity dependence of the detection efficiency and the probability of transitions between the weak-field seeking and strong-field seeking quantum states. Together, the experimental and simulated data provide information about the spatial extent of the source of molecules. We consider the prospects for future trapping and sympathetic cooling experiments.Comment: 14 pages, 6 figures; minor revisions following referee suggestion
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