2,033,636 research outputs found
Daemons and DAMA: Their Celestial-Mechanics Interrelations
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
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 -electron molecular solid RbO
We examine magnon and orbiton behavior in localized O anti-bonding
molecular 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
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
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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