162 research outputs found
On the Opening of Branes
We relate, in 10 and 11 dimensional supergravities, configurations of
intersecting closed branes with vanishing binding energy to configurations
where one of the branes opens and has its boundaries attached to the other.
These boundaries are charged with respect to fields living on the closed brane.
The latter hosts electric and magnetic charges stemming from dual pairs of open
branes terminating on it. We show that charge conservation, gauge invariance
and supersymmetry entirely determine these charges and these fields, which can
be seen as Goldstone fields of broken supersymmetry. Open brane boundary
charges can annihilate, restoring the zero binding energy configuration. This
suggests emission of closed branes by branes, a generalization of closed string
emission by D-branes. We comment on the relation of the Goldstone fields to
matrix models approaches to M-theory.Comment: 13 pages, LaTeX, no figure
Effective superpotential for U(N) with antisymmetric matter
We consider an N=1 U(N) gauge theory with matter in the antisymmetric
representation and its conjugate, with a tree level superpotential containing
at least quartic interactions for these fields. We obtain the effective
glueball superpotential in the classically unbroken case, and show that it has
a non-trivial N-dependence which does not factorize. We also recover additional
contributions starting at order S^N from the dynamics of Sp(0) factors. This
can also be understood by a precise map of this theory to an Sp(2N-2) gauge
theory with antisymmetric matter.Comment: 22 pages. v2: comment (and a reference) added at the end of section 2
on low rank cases; minor typos corrected. v3: 2 footnotes added with
additional clarifications; version to appear in journa
Charting the phase diagram of QCD3
We study the phase diagram of SU (N) gauge theory in three space-time dimensions with a Chern-Simons term at level k, coupled to two sets of fundamental fermions with masses m1 and m2, respectively. The two-dimensional phase diagram that we propose shows a rich structure and widens in an interesting way previous results in the literature, to which it reduces in some limits. We present several checks of our proposal, including consistency with boson/fermion dualities. In this respect, we extensively comment on the structure of the scalar potential which is needed on the bosonic side of the duality
Supersymmetry and Gravitational Duality
We study how the supersymmetry algebra copes with gravitational duality. As a
playground, we consider a charged Taub-NUT solution of D=4, N=2 supergravity.
We find explicitly its Killing spinors, and the projection they obey provides
evidence that the dual magnetic momenta necessarily have to appear in the
supersymmetry algebra. The existence of such a modification is further
supported using an approach based on the Nester form. In the process, we find
new expressions for the dual magnetic momenta, including the NUT charge. The
same expressions are then rederived using gravitational duality.Comment: 23 pages, no figures; v2: sign typos fixed in Section 6; v3: version
to appear in PRD. Improved discussion in section 5 (on the surface NUT
charges) and in section 6 (on the superalgebra
Exploring Holographic General Gauge Mediation
We study models of gauge mediation with strongly coupled hidden sectors,
employing a hard wall background as an holographic dual description. The
structure of the soft spectrum depends crucially on the boundary conditions one
imposes on bulk fields at the IR wall. Generically, vector and fermion
correlators have poles at zero momentum, leading to gauge mediation by massive
vector messengers and/or generating Dirac gaugino masses. Instead, non-generic
choices of boundary conditions let one cover all of GGM parameter space.
Enriching the background with R-symmetry breaking scalars, the SSM soft term
structure becomes more constrained and similar to previously studied top-down
models, while retaining the more analytic control the present bottom-up
approach offers.Comment: 28 pages, 4 figures; v2: typos corrected and refs adde
Cascades with Adjoint Matter: Adjoint Transitions
A large class of duality cascades based on quivers arising from non-isolated
singularities enjoy adjoint transitions - a phenomenon which occurs when the
gauge coupling of a node possessing adjoint matter is driven to strong coupling
in a manner resulting in a reduction of rank in the non-Abelian part of the
gauge group and a subsequent flow to weaker coupling. We describe adjoint
transitions in a simple family of cascades based on a Z2-orbifold of the
conifold using field theory. We show that they are dual to Higgsing and produce
varying numbers of U(1) factors, moduli, and monopoles in a manner which we
calculate. This realizes a large family of cascades which proceed through
Seiberg duality and Higgsing. We briefly describe the supergravity limit of our
analysis, as well as a prescription for treating more general theories. A
special role is played by N=2 SQCD. Our results suggest that additional light
fields are typically generated when UV completing certain constructions of
spontaneous supersymmetry breaking into cascades, potentially leading to
instabilities.Comment: 29 pages, a few typos fixed, improved discussion, added figure; now
there is 1 figur
Tame D-tadpoles in gauge mediation
We revisit models of gauge mediated supersymmetry breaking where messenger
parity is violated. Such a symmetry is usually invoked in order to set to zero
potentially dangerous hypercharge D-term tadpoles. A milder hypothesis is that
the D-tadpole vanishes only at the first order in the gauge coupling constant.
Then the next order leads to a contribution to the sfermion masses which is of
the same magnitude as the usual radiative one. This enlarges the parameter
space of gauge mediated models. We first give a completely general
characterization of this contribution, in terms of particular three-point
functions of hidden sector current multiplet operators. We then explore the
parameter space by means of two simple weakly coupled models, where the
D-tadpole arising at two-loops has actually a mild logarithmic divergence.Comment: 13 pages + 9 pages of appendix, 1 figure; v2: some clarifying
comments added, version to appear in JHE
Soft Spectrum in Yukawa-Gauge Mediation
We introduce a model independent parametrization for a subclass of gauge
mediated theories, which we refer to as Yukawa-gauge mediation. Within this
formalism we study the resulting soft masses in the visible spectrum. We find
general expressions for the gaugino and scalar masses. Under generic
conditions, the gaugino mass is screened, vanishing at first order in the SUSY
breaking scale.Comment: 22 pages, 4 figures; v2: minor corrections, published versio
N=2 Supersymmetric SO(N)/Sp(N) Gauge Theories from Matrix Model
We use the matrix model to describe the N=2 SO(N)/Sp(N) supersymmetric gauge
theories with massive hypermultiplets in the fundamental representation. By
taking the tree level superpotential perturbation made of a polynomial of a
scalar chiral multiplet, the effective action for the eigenvalues of chiral
multiplet can be obtained. By varying this action with respect to an
eigenvalue, a loop equation is obtained. By analyzing this equation, we derive
the Seiberg-Witten curve within the context of matrix model.Comment: 14pp;v2 refs added, clarified in page 4, 6 and 11 and the sign of
resolvent corrected;v3 improved in page 5 and 6 and the flavor dependent part
in the integration around P added and to appear in PR
Four-modulus "Swiss Cheese" chiral models
We study the 'Large Volume Scenario' on explicit, new, compact, four-modulus
Calabi-Yau manifolds. We pay special attention to the chirality problem pointed
out by Blumenhagen, Moster and Plauschinn. Namely, we thoroughly analyze the
possibility of generating neutral, non-perturbative superpotentials from
Euclidean D3-branes in the presence of chirally intersecting D7-branes. We find
that taking proper account of the Freed-Witten anomaly on non-spin cycles and
of the Kaehler cone conditions imposes severe constraints on the models.
Nevertheless, we are able to create setups where the constraints are solved,
and up to three moduli are stabilized.Comment: 40 pages, 10 figures, clarifying comments added, minor mistakes
correcte
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