261 research outputs found
Low-Energy Effective Lagrangian in Unified Theories with Non-Universal Supersymmetry Breaking Terms
Supersymmetric grand unified theories with non-universal soft supersymmetry
breaking terms are studied. By integrating out the superheavy fields at an
unification scale, we compute their low-energy effective Lagrangian. We find
new contributions to the scalar potential specific to the non-universal
supersymmetry breaking. -term contribution to the scalar masses is one
example. The gauge hierarchy achieved by a fine-tuning in the superpotential
would be violated in general due to the non-universal SUSY breaking terms. We
show, however, it is preserved for a certain class of the soft terms derived
from a {\em hidden} ansatz. We also discuss some phenomenological implications
of the non-universal supersymmetry breaking, including predictions of the
radiative electroweak symmetry breaking scenario and of no-scale type models.Comment: 29 pages, LaTeX, DPSU-9402,LBL-35731,UCB-PTH-94/16,TU-45
Establishment of Mareks' Disease Lymphoblastoid Cell Lines from Chickens with B^AB^K of B Blood Groups
Ordering of the Heisenberg spin glass in two dimensions
The spin and the chirality orderings of the Heisenberg spin glass in two
dimensions with the nearest-neighbor Gaussian coupling are investigated by
equilibrium Monte Carlo simulations. Particular attention is paid to the
behavior of the spin and the chirality correlation lengths. In order to observe
the true asymptotic behavior, fairly large system size L\gsim 20 (L the linear
dimension of the system) appears to be necessary. It is found that both the
spin and the chirality order only at zero temperature. At high temperatures,
the chiral correlation length stays shorter than spin correlation length,
whereas at lower temperatures below the crossover temperature T_\times, the
chiral correlation length exceeds the spin correlation length. The spin and the
chirality correlation-length exponents are estimated above T_\times to be
\nu_SG=0.9+-0.2 and \nu_CG=2.1+-0.3, respectively. These values are close to
the previous estimates on the basis of the domain-wall-energy calculation.
Discussion is given about the asymptotic critical behavior realized below
T_\times.Comment: to appear in a special issue of J. Phys.
Electroweak symmetry breaking and s-spectrum in M-theory
We study soft SUSY breaking parameters in M-theory with and without 5-brane
moduli fields. We investigate successful electroweak symmetry breaking and the
positivity of stau mass squared. We study mass spectra in allowed regions.Comment: 34 pages, 24 figure
Itinerant Ferromagnetism in layered crystals LaCoOX (X = P, As)
The electronic and magnetic properties of cobalt-based layered oxypnictides,
LaCoOX (X = P, As), are investigated. LaCoOP and LaCoOAs show metallic type
conduction, and the Fermi edge is observed by hard x-ray photoelectron
spectroscopy. Ferromagnetic transitions occur at 43 K for LaCoOP and 66 K for
LaCoOAs. Above the transition temperatures, temperature dependence of the
magnetic susceptibility follows the Curie-Weiss law. X-ray magnetic circular
dichroism (XMCD) is observed at the Co L2,3-edge, but not at the other edges.
The calculated electronic structure shows a spin polarized ground state. These
results indicate that LaCoOX are itinerant ferromagnets and suggest that their
magnetic properties are governed by spin fluctuation.Comment: 16 pages, 9 figures, Physical Review B, in press. Received 17
February 2008. Accepted 29 May 200
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