20,666 research outputs found
Short-range ordering in face-centered-cubic Ni3Al
Films of fcc Ni3Al with suppressed short-range order (SRO) were prepared by physical vapor deposition of Ni3Al onto room-temperature substrates. Extended electron energy-loss fine-structure spectra were obtained from both Al K and Ni L23 edges. After the samples were annealed for various times at 150 °C, a moderate growth of SRO was observed in the first-nearest-neighbor environments of both the Al and Ni atoms. As prepared, these fcc Ni3Al materials, and presumably others having similar heat evolutions as measured by differential scanning calorimetry, have a high degree of chemical disorder
Meta-Stable Brane Configurations by Adding an Orientifold-Plane to Giveon-Kutasov
In hep-th/0703135, they have found the type IIA intersecting brane
configuration where there exist three NS5-branes, D4-branes and anti-D4-branes.
By analyzing the gravitational interaction for the D4-branes in the background
of the NS5-branes, the phase structures in different regions of the parameter
space were studied in the context of classical string theory. In this paper, by
adding the orientifold 4-plane and 6-plane to the above brane configuration, we
describe the intersecting brane configurations of type IIA string theory
corresponding to the meta-stable nonsupersymmetric vacua of these gauge
theories.Comment: 21 pp, 6 figures; reduced bytes of figures, DBI action analysis added
and to appear in JHE
Meta-Stable Brane Configurations with Seven NS5-Branes
We present the intersecting brane configurations consisting of NS-branes,
D4-branes(and anti D4-branes) and O6-plane, of type IIA string theory
corresponding to the meta-stable nonsupersymmetric vacua in four dimensional
N=1 supersymmetric SU(N_c) x SU(N_c') x SU(N_c'') gauge theory with a symmetric
tensor field, a conjugate symmetric tensor field and bifundamental fields. We
also describe the intersecting brane configurations of type IIA string theory
corresponding to the nonsupersymmetric meta-stable vacua in the above gauge
theory with an antisymmetric tensor field, a conjugate symmetric tensor field,
eight fundamental flavors and bifundamentals. These brane configurations
consist of NS-branes, D4-branes(and anti D4-branes), D6-branes and O6-planes.Comment: 34pp, 9 figures; Improved the draft and added some footnotes; Figure
1, footnote 7 and captions of Figures 7,8,9 added or improved and to appear
in CQ
Supersymmetry Breaking Vacua from M Theory Fivebranes
We consider intersecting brane configurations realizing N=2 supersymmetric
gauge theories broken to N=1 by multitrace superpotentials, and softly to N=0.
We analyze, in the framework of M5-brane wrapping a curve, the supersymmetric
vacua and the analogs of spontaneous supersymmetry breaking and soft
supersymmetry breaking in gauge theories. We show that the M5-brane does not
exhibit the analog of metastable spontaneous supersymmetry breaking, and does
not have non-holomorphic minimal volume curves with holomorphic boundary
conditions. However, we find that any point in the N=2 moduli space can be
rotated to a non-holomorphic minimal volume curve, whose boundary conditions
break supersymmetry. We interpret these as the analogs of soft supersymmetry
breaking vacua in the gauge theory.Comment: 32 pages, 8 figures, harvmac; v2: corrections in eq. 3.6 and in
section 6, reference adde
Meta-Stable Brane Configurations of Triple Product Gauge Groups
From an N=1 supersymmetric electric gauge theory with the gauge group SU(N_c)
x SU(N_c') x SU(N_c'') with fundamentals for each gauge group and the
bifundamentals, we apply Seiberg dual to each gauge group and obtain the N=1
supersymmetric dual magnetic gauge theories with dual matters including the
additional gauge singlets. By analyzing the F-term equations of the dual
magnetic superpotentials, we describe the intersecting brane configurations of
type IIA string theory corresponding to the meta-stable nonsupersymmetric vacua
of this gauge theory. We apply also to the case for N=1 supersymmetric electric
gauge theory with the gauge group Sp(N_c) x SO(2N_c') x Sp(N_c'') with flavors
for each gauge group and the bifundamentals. Finally, we describe the
meta-stable brane configurations of multiple product gauge groups.Comment: 80pp, 10 figures; shorten the draft and to appear in IJMP
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