1,260 research outputs found
R-symmetry breaking, runaway directions and global symmetries in O'Raifeartaigh models
We discuss O'Raifeartaigh models with general R-charge assignments,
introduced by Shih to break R-symmetry spontaneously. We argue that most of
these models have runaway directions related to the R-symmetry. In addition, we
study the simplest model with a U(N) global symmetry and show that in a range
of parameters R-symmetry is spontaneously broken in a metastable vacuum.Comment: 16 pages, 1 figur
Supersymmetry Breaking, R-Symmetry Breaking and Metastable Vacua
Models of spontaneous supersymmetry breaking generically have an R-symmetry,
which is problematic for obtaining gaugino masses and avoiding light R-axions.
The situation is improved in models of metastable supersymmetry breaking, which
generically have only an approximate R-symmetry. Based on this we argue, with
mild assumptions, that metastable supersymmetry breaking is inevitable. We also
illustrate various general issues regarding spontaneous and explicit R-symmetry
breaking, using simple toy models of supersymmetry breaking.Comment: 23 page
A Sequence of Duals for Sp(2N) Supersymmetric Gauge Theories with Adjoint Matter
We consider supersymmetric Sp(2N) gauge theories with F matter fields in the
defining representation, one matter field in the adjoint representation, and no
superpotential. We construct a sequence of dual descriptions of this theory
using the dualities of Seiberg combined with the ``deconfinement'' method
introduced by Berkooz. Our duals hint at a new non-perturbative phenomenon that
seems to be taking place at asymptotically low energies in these theories: for
small F some of the degrees of freedom form massless, non-interacting bound
states while the theory remains in an interacting non-Abelian Coulomb phase.
This phenomenon is the result of strong coupling gauge dynamics in the original
description, but has a simple classical origin in the dual descriptions. The
methods used for constructing these duals can be generalized to any model
involving arbitrary 2-index tensor representations of Sp(2N), SO(N), or SU(N)
groups.Comment: version (with additional references) to appear in Phys. Rev. D, 20
pages, LaTeX, one embedded eps figur
A Systematic Approach to Confinement in N=1 Supersymmetric Gauge Theories
We give necessary criteria for N=1 supersymmetric theories to be in a
smoothly confining phase without chiral symmetry breaking and with a
dynamically generated superpotential. Using our general arguments we find all
such confining SU and Sp theories with a single gauge group and no tree level
superpotential.Comment: 8 pages, LaTe
More on Chiral-Nonchiral Dual Pairs
Expanding upon earlier work of Pouliot and Strassler, we construct chiral
magnetic duals to nonchiral supersymmetric electric theories based upon SO(7),
SO(8) and SO(9) gauge groups with various numbers of vector and spinor matter
superfields. Anomalies are matched and gauge invariant operators are mapped
within each dual pair. Renormalization group flows along flat directions are
also examined. We find that confining phase quantum constraints in the electric
theories are recovered from semiclassical equations of motion in their magnetic
counterparts when the dual gauge groups are completely Higgsed.Comment: 25 pages, harvmac and tables macros, 1 figur
The Dual of Supersymmetric SU(2k) with an Antisymmetric Tensor and Composite Dualities
We suggest a dual to an Susy gauge theory containing an
antisymmetric tensor, \nf fundamentals and \nfb anti-fundamentals. This is
done by expanding the theory into an equivalent description with two gauge
groups and then performing known duality tranformations on each gauge group
separately. Chiral operators, mass perturbations and flat directions are
discussed.Comment: 17 pages, Harvma
On the Z_2 Monopole of Spin(10) Gauge Theories
An "expanded" description is introduced to examine the spinor-monopole
identification proposed by Strassler for four-dimensional = 1
supersymmetric Spin(10) gauge theories with matter in F vector and N spinor
representations. It is shown that a Z_2 monopole in the "expanded" theory is
associated with massive spinors of the Spin(10) theory. For N=2, two spinor
case, we confirm this identification by matching the transformation properties
of the two theories under SU(2) flavor symmetry. However, for N 3, the
transformation properties are not matched between the spinors and the monopole.
This disagreement might be due to the fact that the SU(N) flavor symmetry of
the Spin(10) theory is partially realized as an SU(2) symmetry in the
"expanded" theory.Comment: 16 pages, LaTex, no figur
Conifold Transitions in M-theory on Calabi-Yau Fourfolds with Background Fluxes
We consider topology changing transitions for M-theory compactifications on
Calabi-Yau fourfolds with background G-flux. The local geometry of the
transition is generically a genus g curve of conifold singularities, which
engineers a 3d gauge theory with four supercharges, near the intersection of
Coulomb and Higgs branches. We identify a set of canonical, minimal flux quanta
which solve the local quantization condition on G for a given geometry,
including new solutions in which the flux is neither of horizontal nor vertical
type. A local analysis of the flux superpotential shows that the potential has
flat directions for a subset of these fluxes and the topologically different
phases can be dynamically connected. For special geometries and background
configurations, the local transitions extend to extremal transitions between
global fourfold compactifications with flux. By a circle decompactification the
M-theory analysis identifies consistent flux configurations in four-dimensional
F-theory compactifications and flat directions in the deformation space of
branes with bundles.Comment: 93 pages; v2: minor changes and references adde
A search for solar wind velocity changes between 0.7 and 1 AU
Simultaneous observations of the solar wind velocity as measured at the Pioneer 9 and Ogo 5 spacecraft during five solar rotations in 1968 and 1969 are presented. During this time, Pioneer 9 was traveling in toward the sun to approximately 0.7 AU while the earth orbiter Ogo 5 was spending long periods in the interplanetary medium. A comparison of the 3-hour averages of solar wind velocity obtained at both spacecraft indicates that the same basic solar wind velocity structure was seen at both spacecraft. There was no statistically significant dependence of average velocity on radial distance from the sun. The amplitude of variations about the average velocity apparently decreased with increasing distance from the sun; some but probably not all of this decreased variation is consistent with the exchange of momentum between high-velocity and low-velocity streams. The correlation coefficient of pairs of velocity averages computed from a corotation model decreases with increasing distance between the two spacecraft
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