6,970 research outputs found
Recent Developments in Superstring Phenomenology
Recent developments in superstring phenomenology are summarized on a
non-technical level. (Talk presented at the XXVIIth Rencontre de Moriond on
Electroweak Interactions and Unified Theories.)Comment: 13 page
Supersymmetric AdS_7 backgrounds in half-maximal supergravity and marginal operators of (1,0) SCFTs
We determine the supersymmetric AdS_7 backgrounds of seven-dimensional
half-maximal gauged supergravities and show that they do not admit any
deformations that preserve all 16 supercharges. We compare this result to the
conformal manifold of the holographically dual (1,0) superconformal field
theories and show that accordingly its representation theory implies that no
supersymmetric marginal operators exist.Comment: 20 pages, corrected classification of non-semisimple gauge groups,
version to appear in JHE
AdS vacua from type IIB supergravity on
We study maximally supersymmetric Anti-de Sitter backgrounds in consistent
N=2 truncations of type IIB supergravity compactified on the Sasaki-Einstein
manifold . In particular, we focus on truncations that contain fields
coming from the nontrivial second and third cohomology forms on .
These give rise to N=2 supergravity coupled to two vector- and two
hypermultiplets (Betti-vector truncation) or one vector- and three
hypermultiplets (Betti-hyper truncation), respectively. We find that both
truncations admit AdS backgrounds with the gauge group always being broken
but containing at least an factor. Moreover, in both cases we show
that the moduli space of AdS vacua is nontrivial and of maximal dimension.
Finally, we explicitly compute the metrics on these moduli spaces.Comment: 20 pages; v2: updated references; v3: 21 pages, as published in JHE
Hiding the little hierarchy problem in the NMSSM
In this paper we consider a set of soft supersymmetry breaking terms within
the NMSSM which leads to a small hierarchy between the supersymmetry breaking
scale and the electroweak scale. Specifically only the gaugino masses and the
soft term in the Higgs sector are non-vanishing at the GUT scale. This pattern
can be found in gaugino mediated models and in higher-dimensional orbifold
GUTs. We study the phenomenology of this scenario and find different low energy
spectra depending on the Yukawa coupling of the NMSSM singlet. In
particular, for low values of the singlet is the lightest scalar and
the singlino is the LSP while for large values of both are heavy and
the gravitino can be the LSP. The singlet pseudoscalar is very light in the
entire parameter space.Comment: Latex, 21+1 pages, 5 figures; v2: References and comments adde
Classification of maximally supersymmetric backgrounds in supergravity theories
We study maximally supersymmetric solutions of all gauged or deformed
supergravity theories in space-time dimensions. For vanishing
background fluxes the space-time background has to be either Minkowski or
anti-de Sitter. We derive a simple criterion for the existence of solutions
with non-trivial fluxes and determine all supergravities that satisfy it. We
show that their solutions coincide with those of the corresponding ungauged
theories and conclude that the known list of maximally supersymmetric solutions
is exhaustive.Comment: 25 pages; improved discussion of the gauged R-symmetry, references
added, version to be published in JHE
Maximally Supersymmetric AdS4 Vacua in N=4 Supergravity
We study AdS backgrounds of N=4 supergravity in four space-time dimensions
which preserve all sixteen supercharges. We show that the graviphotons have to
form a subgroup of the gauge group that consists of an electric and a magnetic
SO(3)_+ x SO(3)_-. Moreover, these N=4 AdS backgrounds are necessarily isolated
points in field space which have no moduli.Comment: 11 page
Examples of N=2 to N=1 supersymmetry breaking
In this paper we consider gauged N=2 supergravities which arise in the
low-energy limit of type II string theories and study examples which exhibit
spontaneous partial supersymmetry breaking. For the quantum STU model we derive
the scalar field space and the scalar potential of the N=1 supersymmetric
low-energy effective action. We also study the properties of the Minkowskian
N=1 supersymmetricground states for a broader class of supergravities including
the quantum STU model.Comment: 22 pages, added references, version to appear in JHE
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