147 research outputs found
Dynamical Supersymmetry Breaking and the Linear Multiplet
We analyze gaugino condensation in the presence of a dilaton and an
antisymmetric tensor field, with couplings reminiscent of string theories. The
degrees of freedom relevant to a supersymmetric description of the effective
theory below the scale of condensation are discussed in this context.Comment: 17 pages, LaTeX, no figures -- 1 reference correcte
Dilaton, moduli and string/five-brane duality as seen from four dimensions
A naive dimensional reduction of the supergravity theory that
naturally arises in five-brane models is used to determine the r\^ole of two
fields which are basic ingredients of string models: the dilaton and, among the
moduli, the breathing mode. It is shown that, under the duality transformation
that relates five-branes and strings, these two fields exchange the r\^oles of
10-dimensional dilaton and radius of the compact manifold. A description of
this phenomenon in terms of the linear multiplets of the 4-dimensional
supergravity is also presented.Comment: 14 pages, Latex, NSF-ITP-93-6
Couplings of N=1 chiral spinor multiplets
We derive the action for chiral spinor multiplets coupled to vector and
scalar multiplets. We give the component form of the action, which contains
gauge invariant mass terms for the antisymmetric tensors in the spinor
superfield and additional Green-Schwarz couplings to vector fields. We observe
that supersymmetry provides mass terms for the scalars in the spinor multiplet
which do not arise from eliminating an auxiliary field. We construct the dual
action by explicitly performing the duality transformations in superspace and
give its component form.Comment: 17 pages, v2 small change
Gaugino Condensation with S-Duality and Field-Theoretical Threshold Corrections
We study gaugino condensation in the presence of an intermediate mass scale
in the hidden sector. S-duality is imposed as an approximate symmetry of the
effective supergravity theory. Furthermore, we include in the K\"ahler
potential the renormalization of the gauge coupling and the one-loop threshold
corrections at the intermediate scale. It is shown that confinement is indeed
achieved. Furthermore, a new running behaviour of the dilaton arises which we
attribute to S-duality. We also discuss the effects of the intermediate scale,
and possible phenomenological implications of this model.Comment: 19 pages, LaTeX, 3 postscript figures include
Gaugino Condensation in N=1 Supergravity Models with Multiple Dilaton-Like Fields
We study supersymmetry breaking by hidden-sector gaugino condensation in N=1
D=4 supergravity models with multiple dilaton-like moduli fields. Our work is
motivated by Type I string theory, in which the low-energy effective Lagrangian
can have different dilaton-like fields coupling to different sectors of the
theory. We construct the effective Lagrangian for gaugino condensation and use
it to compute the visible-sector gaugino masses. We find that the gaugino
masses can be of order the gravitino mass, in stark contrast to heterotic
string models with a single dilaton field.Comment: LaTeX, 17 pages, 2 eps figure
GAUGINO CONDENSATES AND CHIRAL-LINEAR DUALITY: AN EFFECTIVE LAGRANGIAN ANALYSIS
We show how to formulate the phenomenon of gaugino condensation in a
super-Yang-Mills theory with a field-dependent gauge coupling described with a
linear multiplet. We prove the duality equivalence of this approach with the
more familiar formulation using a chiral superfield. In so doing, we resolve a
longstanding puzzle as to how a linear-multiplet formulation can be consistent
with the dynamical breaking of the Peccei-Quinn symmetry which is thought to
occur once the gauginos condense. In our approach, the composite gauge degrees
of freedom are described by a real vector superfield, , rather than the
chiral superfield that is obtained in the traditional dual formulation. Our
dualization, when applied to the case of several condensing gauge groups,
provides strong evidence that this duality survives strong-coupling effects in
string theory.Comment: We have improved our discussion of the case where several factors of
the gauge group condense. We also show that the antisymmetric tensor acquires
a mass in this case in a novel way
Calabi-Yau Fourfolds with Flux and Supersymmetry Breaking
In Calabi-Yau fourfold compactifications of M-theory with flux, we
investigate the possibility of partial supersymmetry breaking in the
three-dimensional effective theory. To this end, we place the effective theory
in the framework of general N=2 gauged supergravities, in the special case
where only translational symmetries are gauged. This allows us to extract
supersymmetry-breaking conditions, and interpret them as conditions on the
4-form flux and Calabi-Yau geometry. For N=2 unbroken supersymmetry in three
dimensions we recover previously known results, and we find a new condition for
breaking supersymmetry from N=2 to N=1, i.e. from four to two supercharges. An
example of a Calabi-Yau hypersurface in a toric variety that satisfies this
condition is provided.Comment: 26 page
One-Loop Pauli-Villars Regularization of Supergravity I: Canonical Gauge Kinetic Energy
It is shown that the one-loop coefficients of on-shell operators of standard
supergravity with canonical gauge kinetic energy can be regulated by the
introduction of Pauli-Villars chiral and abelian gauge multiplets, subject to a
condition on the matter representations of the gauge group. Aspects of the
anomaly structure of these theories under global nonlinear symmetries and an
anomalous gauge symmetry are discussed.Comment: 46 pages, full postscript also available from
http://phyweb.lbl.gov/theorygroup/papers/preprints.html/41981.ps . Misprints
and errors in equations present in the original version have been correcte
One-loop Regularization of Supergravity II: The Dilaton and the Superfield Formulation
The on-shell regularization of the one-loop divergences of supergravity
theories is generalized to include a dilaton of the type occurring in effective
field theories derived from superstring theory, and the superfield structure of
the one-loop corrections is given. Field theory anomalies and quantum
contributions to soft supersymmetry breaking are discussed. The latter are
sensitive to the precise choice of couplings that generate Pauli-Villars
masses, which in turn reflect the details of the underlying theory above the
scale of the effective cut-off. With a view to the implementation the
Green-Schwarz and other mechanisms for canceling field theory anomalies under a
U(1) gauge transformation and under the T-duality group of modular
transformations, we show that the K\"ahler potential renormalization for the
untwisted sector of orbifold compactification can be made invariant under these
groups.Comment: 46 pages, full postscript also available from
http://phyweb.lbl.gov/theorygroup/papers/43259.p
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