317 research outputs found
The Romelsberger Index, Berkooz Deconfinement, and Infinite Families of Seiberg Duals
Romelsberger's index has been argued to be an RG-invariant and, therefore,
Seiberg-duality-invariant object that counts protected operators in the IR SCFT
of an N=1 theory. These claims have so far passed all tests. In fact, it
remains possible that this index is a perfect discriminant of duality. The
investigation presented here bolsters such optimism. It is shown that the
conditions of total ellipticity, which are needed for the mathematical
manifestation of duality, are equivalent to the conditions ensuring
non-anomalous gauge and flavor symmetries and the matching of (most) 't Hooft
anomalies. Further insights are gained from an analysis of recent results by
Craig, et al. It is shown that a non-perturbative resolution of an apparent
mismatch of global symmetries is automatically accounted for in the index. It
is then shown that through an intricate series of dynamical steps, the index
not only remains fixed, but the only integral relation needed is the one that
gives the "primitive" Seiberg dualities, perhaps hinting that the symmetry at
the core is fundamental rather than incidental.Comment: 47 pages; some typos correcte
Comments on General Gauge Mediation
There has been interest in generalizing models of gauge mediation of
supersymmetry breaking. As shown by Meade, Seiberg, and Shih (MSS), the soft
masses of general gauge mediation can be expressed in terms of the current
two-point functions of the susy-breaking sector. We here give a simple
extension of their result which provides, for general gauge mediation, the full
effective potential for squark pseudo-D-flat directions. The effective
potential reduces to the sfermion soft masses near the origin, and the full
potential, away from the origin, can be useful for cosmological applications.
We also generalize the soft masses and effective potential to allow for general
gauge mediation by Higgsed gauge groups. Finally, we discuss general gauge
mediation in the limit of small F-terms, and how the results of MSS connect
with the analytic continuation in superspace results, based on a spurion
analysis.Comment: 11 pages, 2 figures, references adde
A CP-safe solution of the μ/Bμ problem of gauge mediation
AbstractWe construct a model that naturally generates μ and B of the same order without producing large CP violating phases. This is easily accomplished once one permits these mass scales to be determined independently of the ordinary gauge-mediated soft masses. The alignment of phases is shown to emerge dynamically upon coupling to supergravity and is not unique to the model presented here
Higgs Messengers
We explore the consequences of the Higgs fields acting as messengers of
supersymmetry breaking. The hidden-sector paradigm in the gauge mediation
framework is relaxed by allowing two types of gauge-invariant, renormalizable
operators that are typically discarded: direct coupling between the Higgses and
supersymmetry breaking singlets, and Higgs-messenger mixing terms. The most
important phenomenological consequence is a flavor-dependent shift in sfermion
masses. This is from a one-loop contribution, which we compute for a general
set of weak doublet messengers. We also study a couple of explicit models in
detail, finding that precision electroweak constraints can be satisfied with a
spectrum significantly different from that of gauge mediation.Comment: 20 pages, 5 figure
Surveying Pseudomoduli: the Good, the Bad and the Incalculable
We classify possible types of pseudomoduli which arise when supersymmetry is
dynamically broken in infrared-free low-energy theories. We show that, even if
the pseudomoduli potential is generated only at higher loops, there is a regime
where the potential can be simply determined from a combination of one-loop
running data. In this regime, we compute whether the potential for the various
types of pseudomoduli is safe, has a dangerous runaway to the UV cutoff of the
low-energy theory, or is incalculable. Our results are applicable to building
new models of supersymmetry breaking. We apply the results to survey large
classes of models.Comment: 34 page
Testing the Nambu-Goldstone Hypothesis for Quarks and Leptons at the LHC
The hierarchy of the Yukawa couplings is an outstanding problem of the
standard model. We present a class of models in which the first and second
generation fermions are SUSY partners of pseudo-Nambu-Goldstone bosons that
parameterize a non-compact Kahler manifold, explaining the small values of
these fermion masses relative to those of the third generation. We also provide
an example of such a model. We find that various regions of the parameter space
in this scenario can give the correct dark matter abundance, and that nearly
all of these regions evade other phenomenological constraints. We show that for
gluino mass ~700 GeV, model points from these regions can be easily
distinguished from other mSUGRA points at the LHC with only 7 fb^(-1) of
integrated luminosity at 14 TeV. The most striking signatures are a dearth of
b- and tau-jets, a great number of multi-lepton events, and either an
"inverted" slepton mass hierarchy, narrowed slepton mass hierarchy, or
characteristic small-mu spectrum.Comment: Corresponds to published versio
Global Symmetries and D-Terms in Supersymmetric Field Theories
We study the role of D-terms in supersymmetry (SUSY) breaking. By carefully
analyzing the SUSY multiplets containing various conserved currents in theories
with global symmetries, we obtain a number of constraints on the
renormalization group flow in supersymmetric field theories. Under broad
assumptions, these results imply that there are no SUSY-breaking vacua, not
even metastable ones, with parametrically large D-terms. This explains the
absence of such D-terms in models of dynamical SUSY-breaking. There is,
however, a rich class of calculable models which generate comparable D-terms
and F-terms through a variety of non-perturbative effects; these D-terms can be
non-abelian. We give several explicit examples of such models, one of which is
a new calculable limit of the 3-2 model.Comment: 34 pages, 2 figures; reference added, minor change
General Gauge Mediation with Gauge Messengers
We generalize the General Gauge Mediation formalism to allow for the
possibility of gauge messengers. Gauge messengers occur when charged matter
fields of the susy-breaking sector have non-zero F-terms, which leads to
tree-level, susy-breaking mass splittings in the gauge fields. A classic
example is that SU(5) / SU(3) x SU(2) x U(1) gauge fields could be gauge
messengers. We give a completely general, model independent, current-algebra
based analysis of gauge messenger mediation of susy-breaking to the visible
sector. Characteristic aspects of gauge messengers include enhanced
contributions to gaugino masses, (tachyonic) sfermion mass-squareds generated
already at one loop, and also at two loops, and significant one-loop A-terms,
already at the messenger scale.Comment: 79 pages, 5 figure
- …