47,755 research outputs found
Takahashi Integral Equation and High-Temperature Expansion of the Heisenberg Chain
Recently a new integral equation describing the thermodynamics of the 1D
Heisenberg model was discovered by Takahashi. Using the integral equation we
have succeeded in obtaining the high temperature expansion of the specific heat
and the magnetic susceptibility up to O((J/T)^{100}). This is much higher than
those obtained so far by the standard methods such as the linked-cluster
algorithm. Our results will be useful to examine various approximation methods
to extrapolate the high temperature expansion to the low temperature region.Comment: 5 pages, 4 figures, 2 table
Axial Charges of Octet Baryons in Two-flavor Lattice QCD
We evaluate the strangeness-conserving , , ,
and the strangeness-changing , ,
, axial charges in lattice QCD with two flavors of
dynamical quarks and extend our previous work on
pseudoscalar-meson-octet-baryon coupling constants so as to include
, and coupling constants. We find that
the axial charges have rather weak quark-mass dependence and the breaking in
SU(3)-flavor symmetry is small at each quark-mass point we consider.Comment: 6 pages, 6 figures. Added discussions and a figure; version to appear
in Physics Letters
Axial Charges of Octet Baryons in Two-flavor Lattice QCD
We evaluate the strangeness-conserving , , ,
and the strangeness-changing , ,
, axial charges in lattice QCD with two flavors of
dynamical quarks and extend our previous work on
pseudoscalar-meson-octet-baryon coupling constants so as to include
, and coupling constants. We find that
the axial charges have rather weak quark-mass dependence and the breaking in
SU(3)-flavor symmetry is small at each quark-mass point we consider.Comment: 6 pages, 6 figures. Added discussions and a figure; version to appear
in Physics Letters
New technique for producing a strong multi-pole magnet
A new technique for producing strong multipole magnet is developed. A cylindrical magnet oriented with its easy axis of magnetization perpendicular to the cylinder axis is magnetized by a multipole magnetizer. This procedure results in a multipole magnet with a flux density almost sixty percent greater than the flux density produced by a multi-pole magnet which is not oriented. The technique is especially effective for producing small cylindrical magnets with many poles and agreement of a theoretical analysis with experimental results is very good, with deviations of no more than a few percent.</p
A look inside charmed-strange baryons from lattice QCD
The electromagnetic form factors of the spin-3/2 baryons, namely
, , and , are
calculated in full QCD on PACS-CS lattices with a pion mass of
156(9) MeV. The electric charge radii and magnetic moments from the and
multipole form factors are extracted. Results for the electric quadrupole
form factors, , are also given. Quark sector contributions are computed
individually for each observable and then combined to obtain the baryon
properties. We find that the charm quark contributions are systematically
smaller than the strange-quark contributions in the case of the charge radii
and magnetic moments. moments of the and
provide a statistically significant data to conclude that their electric charge
distributions are deformed to an oblate shape. Properties of the spin-1/2
and baryons are also computed and a thorough
comparison is given. This complete study gives valuable hints about the
heavy-quark dynamics in charmed hadrons.Comment: 14 pages, 14 figures. Includes a subsection on the systematic effect
Factorization, reduction and embedding in integrable cellular automata
Factorized dynamics in soliton cellular automata with quantum group symmetry
is identified with a motion of particles and anti-particles exhibiting pair
creation and annihilation. An embedding scheme is presented showing that the
D^{(1)}_n-automaton contains, as certain subsectors, the box-ball systems and
all the other automata associated with the crystal bases of non-exceptional
affine Lie algebras. The results extend the earlier ones to higher
representations by a certain reduction and to a wider class of boundary
conditions.Comment: LaTeX2e, 20 page
Smallness of Baryon Asymmetry from Split Supersymmetry
The smallness of the baryon asymmetry in our universe is one of the greatest
mysteries and may originate from some profound physics beyond the standard
model. We investigate the Affleck-Dine baryogenesis in split supersymmetry, and
find that the smallness of the baryon asymmetry is directly related to the
hierarchy between the supersymmetry breaking squark/slepton masses and the weak
scale. Put simply, the baryon asymmetry is small because of the split mass
spectrum.Comment: 4 pages, no figur
- …