620 research outputs found
Self-Consistent Pushing and Cranking Corrections to the Meson Fields of the Chiral Quark-Loop Soliton
We study translational and spin-isospin symmetry restoration for the
two-flavor chiral quark-loop soliton. Instead of a static soliton at rest we
consider a boosted and rotating hedgehog soliton. Corrected classical meson
fields are obtained by minimizing a corrected energy functional which has been
derived by semi-classical methods ('variation after projection'). We evaluate
corrected meson fields in the region 300 MeV \le M \le 600 MeV of constituent
quark masses M and compare them with the uncorrected fields. We study the
effect of the corrections on various expectation values of nuclear observables
such as the root-mean square radius, the axial-vector coupling constant,
magnetic moments and the delta-nucleon mass splitting.Comment: 19 pages, LaTeX, 7 postscript figures included using 'psfig.sty', to
appear in Int.J.Mod.Phys.
Weak continuous monitoring of a flux qubit using coplanar waveguide resonator
We study a flux qubit in a coplanar waveguide resonator by measuring
transmission through the system. In our system with the flux qubit decoupled
galvanically from the resonator, the intermediate coupling regime is achieved.
In this regime dispersive readout is possible with weak backaction on the
qubit. The detailed theoretical analysis and simulations give a good agreement
with the experimental data and allow to make the qubit characterization.Comment: 4 pages, 3 figures, to be published in Phys. Rev.
Chemical Vapor Deposition of High Quality Graphene Films from Carbon Dioxide Atmospheres
Structure of strongly coupled, multi-component plasmas
We investigate the short-range structure in strongly coupled fluidlike plasmas using the hypernetted chain approach generalized to multicomponent systems. Good agreement with numerical simulations validates this method for the parameters considered. We found a strong mutual impact on the spatial arrangement for systems with multiple ion species which is most clearly pronounced in the static structure factor. Quantum pseudopotentials were used to mimic diffraction and exchange effects in dense electron-ion systems. We demonstrate that the different kinds of pseudopotentials proposed lead to large differences in both the pair distributions and structure factors. Large discrepancies were also found in the predicted ion feature of the x-ray scattering signal, illustrating the need for comparison with full quantum calculations or experimental verification
Trapping Solids at the Inner Edge of the Dead Zone: 3-D Global MHD Simulations
The poorly-ionized interior of the protoplanetary disk is the location where
dust coagulation processes may be most efficient. However even here,
planetesimal formation may be limited by the loss of solid material through
radial drift, and by collisional fragmentation of the particles. Our aim is to
investigate the possibility that solid particles are trapped at local pressure
maxima in the dynamically evolving disk. We perform the first 3-D global
non-ideal MHD calculations of the disk treating the turbulence driven by the
magneto-rotational instability. The domain contains an inner MRI-active region
near the young star and an outer midplane dead zone, with the transition
between the two modeled by a sharp increase in the magnetic diffusivity. The
azimuthal magnetic fields generated in the active zone oscillate over time,
changing sign about every 150 years. We thus observe the radial structure of
the `butterfly pattern' seen previously in local shearing-box simulations. The
mean magnetic field diffuses from the active zone into the dead zone, where the
Reynolds stress nevertheless dominates. The greater total accretion stress in
the active zone leads to a net reduction in the surface density, so that after
800 years an approximate steady state is reached in which a local radial
maximum in the midplane pressure lies near the transition radius. We also
observe the formation of density ridges within the active zone. The dead zone
in our models possesses a mean magnetic field, significant Reynolds stresses
and a steady local pressure maximum at the inner edge, where the outward
migration of planetary embryos and the efficient trapping of solid material are
possible.Comment: 17 pages, 30 *.ps files for figures. Accepted 16 November 2009 in A&
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