4,919 research outputs found
Skyrme Strings
We construct nontopological string solutions with U(1) Noether charge in the
Skyrme model with a pion mass term, and examine their stability by taking
linear perturbations. The solution exhibits a critical angular velocity beyond
which the configuration energetically prefers to decay by emitting pions. This
critical point is observed as a cusp in the relation between energy and charge.
We find that the maximum length for the string to be stable is comparable to
the size of one skyrmion. Beyond the length, it is unstable to decay. This
instability raises the possiblity of dynamical realization of Skyrme strings
from monopole strings inside a domain wall.Comment: 7 pages, 3 figures, references adde
Spontaneous Magnetization through Non-Abelian Vortex Formation in Rotating Dense Quark Matter
When a color superconductor of high density QCD is rotating, superfluid
vortices are inevitably created along the rotation axis. In the color-flavor
locked phase realized at the asymptotically large chemical potential, there
appear non-Abelian vortices carrying both circulations of superfluid and color
magnetic fluxes. A family of solutions has a degeneracy characterized by the
Nambu-Goldtone modes CP2, associated with the color-flavor locked symmetry
spontaneously broken in the vicinity of the vortex. In this paper, we study
electromagnetic coupling of the non-Abelian vortices and find that the
degeneracy is removed with the induced effective potential. We obtain one
stable vortex solution and a family of metastable vortex solutions, both of
which carry ordinary magnetic fluxes in addition to color magnetic fluxes. We
discuss quantum mechanical decay of the metastable vortices by quantum
tunneling, and compare the effective potential with the other known potentials,
the quantum mechanically induced potential and the potential induced by the
strange quark mass.Comment: 24 pages, 4 figures; v2 revised published versio
Charged Particle Dynamics in the Field of a Slowly Rotating Compact Star
We study the dynamics of a charged particle in the field of a slowly rotating
compact star in the gravitoelectromagnetic approximation to the geodesic
equation . The star is assumed to be surrounded by an ideal, highly conducting
plasma (taken as a magnetohydrodynamic fluid) with a stationary, axially
symmetric electromagnetic field. The general relativistic Maxwell equations are
solved to obtain the effects of the background spacetime on the electromagnetic
field in the linearized Kerr spacetime. The equations of motion are then set up
and solved numerically to incorporate the gravitational as well as the
electromagnetic effects. The analysis shows that in the slow rotation
approximation the frame dragging effects on the electromagnetic field are
absent. However the particle is directly effected by the rotating gravitational
source such that close to the star the gravitational and electromagnetic field
produce contrary effects on the particle's trajectory.Comment: 10 pages, 6 figures in B & W PostScript Forma
The applicability of the catalytic wet-oxidation to CELSS
The wet oxidation catalysis of Au, Pd, Pt, Rh or Ru on a ceramic honeycomb carrier was traced in detail by 16 to 20 repetitive batch tests each. As a result, Pt or Pd on a honeycomb carrier was shown to catalyze complete nitrogen gasification as N2. Though the catalysts which realize both complete nitrogen gasification and complete oxidation could not be found, the Ru+Rh catalyst was found to be most promising. Ru honeycomb catalyzed both nitrification and nitrogen gasification
Coronal propagation of solar flare particles observed by satellite
Propagation of solar flare particles in corona was studied using the satellite data at the geostationary orbit. by selecting very fast rise time events only, the interplanetary propagation were assumed to be scatter free arrival. The results show that the propagation in corona does not depend on particle energy in 4 to 500 MeV protons, and the time delays from optical flare do not depend on the distance between the flare site and the base of the interplanetary magnetic field which connects to the Earth
High-temperature, high-pressure spherical segment valve Patent
High-temperature, high-pressure spherical segment valv
Spin-Hall effect in two-dimensional mesoscopic hole systems
The spin Hall effect in two dimensional hole systems is studied by using the
four-terminal Landauer-B\"{u}ttiker formula with the help of Green functions.
The spin Hall effect exists even when there are {\em not} any correlations
between the spin-up and -down heavy holes (light holes) and when the
-point degeneracy of the heavy hole and light hole bands is lifted by
the confinement or recovered by the strain. When only a heavy hole charge
current without any spin polarization is injected through one lead, under right
choice of lead voltages, one can get a pure heavy (light) hole spin current,
combined with a possible impure light (heavy) hole spin current from another
two leads. The spin Hall coefficients of both heavy and light holes depend on
the Fermi energy, devise size and the disorder strength. It is also shown that
the spin Hall effect of two dimensional hole systems is much more robust than
that of electron systems with the Rashba spin-orbit coupling and the spin Hall
coefficients do not decrease with the system size but tend to some nonzero
values when the disorder strength is smaller than some critical value.Comment: 5 pages, 4 figure
Non-Abelian statistics of vortices with non-Abelian Dirac fermions
We extend our previous analysis on the exchange statistics of vortices having
a single Dirac fermion trapped in each core, to the case where vortices trap
two Dirac fermions with U(2) symmetry. Such a system of vortices with
non-Abelian Dirac fermions appears in color superconductors at extremely high
densities, and in supersymmetric QCD. We show that the exchange of two vortices
having doublet Dirac fermions in each core is expressed by non-Abelian
representations of a braid group, which is explicitly verified in the matrix
representation of the exchange operators when the number of vortices is up to
four. We find that the result contains the matrices previously obtained for the
vortices with a single Dirac fermion in each core as a special case. The whole
braid group does not immediately imply non-Abelian statistics of identical
particles because it also contains exchanges between vortices with different
numbers of Dirac fermions. However, we find that it does contain, as its
subgroup, a genuine non-Abelian statistics for the exchange of the identical
particles, that is, vortices with the same number of Dirac fermions. This
result is surprising compared with conventional understanding because all Dirac
fermions are defined locally at each vortex, unlike the case of Majorana
fermions for which Dirac fermions are defined non-locally by Majorana fermions
located at two spatially separated vortices.Comment: 32 pages, no figures, v3: published versio
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