83,876 research outputs found
Running of Soft Parameters in Extra Space-Time Dimensions
The evolution of the parameters including those in the soft
supersymmetry-breaking (SSB) sector is studied in the minimal supersymmetric
standard model (MSSM) with a certain set of Kaluza-Klein towers which has been
recently considered by Dienes et al. We use the continuous Wilson
renormalizaion group technique to derive the matching condition between the
effective, renormalizable and original, unrenormalizable theories. We
investigate whether the assumption on a large compactification radius in the
model is consistent with the gauge coupling unification, the
unification and the radiative breaking of the electroweak gauge symmetry with
the universal SSB terms. We calculate the superpartner spectrum under the
assumption of the universal SSB parameters to find differences between the
model and the MSSM.Comment: 32 pages, latex, 14 figure
Precision Corrections to Supersymmetric Unification
We compute the full set of weak-scale gauge and Yukawa threshold corrections
in the minimal supersymmetric standard model, including all finite
(non-logarithmic) corrections, which we show to be important. We use our
results to examine the effects of unification-scale threshold corrections in
the minimal and missing-doublet SU(5) models. We work in the context of a
unified mass spectrum, with scalar mass M_0 and gaugino mass M_1/2, and find
that in minimal SU(5) with squark masses less than one TeV, successful gauge
and Yukawa coupling unification requires M_1/2 << M_0 and M_0 \simeq 1 TeV. In
contrast, we find that the missing-doublet model permits gauge and Yukawa
unification for a wide range of supersymmetric masses.Comment: 11 pages, 6 figures included, uses epsf.te
Hierarchical neutrino masses and mixing in non minimal-SU(5)
We consider the problem of neutrino masses and mixing within the framework of
a non-minimal supersymmetric SU(5) model extended by adding a set of 1,24
chiral superfields accommodating three right-handed neutrinos. A Type I+III
see-saw mechanism can then be realized giving rise to a hierarchical mass
spectrum for the light neutrinos of the form m_3> m_2>> m_1 consistent with
present data. The extra colored states are pushed to the unification scale by
proton stability constraints, while the intermediate see-saw energy scale and
the unification scale are maintained in phenomenologically acceptable ranges.
We also examine the issue of large neutrino mixing hierarchy \theta_{23}>
\theta_{12}>> \theta_{13} in the above framework of hierarchical neutrino
masses.Comment: 12 pages, 1 figure, 1 table. Captions inserted, 2 sentences for
clarification added, 2 references adde
Term-Graph Anti-Unification
We study anti-unification for possibly cyclic, unranked term-graphs and develop an algorithm, which computes a minimal complete set of generalizations for them. For bisimilar graphs the algorithm computes the join in the lattice generated by a functional bisimulation. These results generalize anti-unification for ranked and unranked terms to the corresponding term-graphs, and solve also anti-unification problems for rational terms and dags. Our results open a way to widen anti-unification based code clone detection techniques from a tree representation to a graph representation of the code
Matter Unification in Warped Supersymmetric SO(10)
We construct models of warped unification with a bulk SO(10) gauge symmetry
and boundary conditions that preserve the SU(4)_C x SU(2)_L x SU(2)_R
Pati-Salam gauge group (422). In the dual 4D description, these models are 422
gauge theories in which the apparent unification of gauge couplings in the
minimal supersymmetric standard model is explained as a consequence of strong
coupling in the ultraviolet. The weakness of the gauge couplings at low
energies is ensured in this 4D picture by asymptotically non-free contributions
from the conformal sector, which are universal due to an approximate SO(10)
global symmetry. The 422 gauge symmetry is broken to the standard model group
by a simple set of Higgs fields. An advantage of this setup relative to SU(5)
models of warped unification is that matter is automatically required to fill
out representations of 422, providing an elegant understanding of the quantum
numbers of the standard-model quarks and leptons. The models also naturally
incorporate the see-saw mechanism for neutrino masses and bottom-tau
unification. Finally, they predict a rich spectrum of exotic particles near the
TeV scale, including states with different quantum numbers than those that
appear in SU(5) models.Comment: 19 pages, Latex, version to appear in Nucl. Phys.
Unital Anti-Unification: Type and Algorithms
Unital equational theories are defined by axioms that assert the existence of the unit element for some function symbols. We study anti-unification (AU) in unital theories and address the problems of establishing generalization type and designing anti-unification algorithms. First, we prove that when the term signature contains at least two unital functions, anti-unification is of the nullary type by showing that there exists an AU problem, which does not have a minimal complete set of generalizations. Next, we consider two special cases: the linear variant and the fragment with only one unital symbol, and design AU algorithms for them. The algorithms are terminating, sound, complete, and return tree grammars from which the set of generalizations can be constructed. Anti-unification for both special cases is finitary. Further, the algorithm for the one-unital fragment is extended to the unrestricted case. It terminates and returns a tree grammar which produces an infinite set of generalizations. At the end, we discuss how the nullary type of unital anti-unification might affect the anti-unification problem in some combined theories, and list some open questions
Reconstruction of Fundamental SUSY Parameters
We summarize methods and expected accuracies in determining the basic
low-energy SUSY parameters from experiments at future ee linear
colliders in the TeV energy range, combined with results from LHC. In a second
step we demonstrate how, based on this set of parameters, the fundamental
supersymmetric theory can be reconstructed at high scales near the grand
unification or Planck scale. These analyses have been carried out for minimal
supergravity [confronted with GMSB for comparison], and for a string effective
theory.Comment: 8 pages, latex, 7 figures, expanded version of contributions to the
proceedings of ICHEP.2002 (Amstersdam) and LCWS.2002 (Jeju Island
Sparticle Mass Spectra from SO(10) Grand Unified Models with Yukawa Coupling Unification
We examine the spectrum of superparticles obtained from the minimal SO(10)
grand unified model, where it is assumed the gauge symmetry breaking yields the
Minimal Supersymmetric Standard Model (MSSM) as the effective theory at
GeV. In this model, unification of Yukawa
couplings implies a value of . At such high values of
, assuming universality of scalar masses, the usual mechanism of
radiative electroweak symmetry breaking breaks down. We show that a set of weak
scale sparticle masses consistent with radiative electroweak symmetry breaking
can be generated by imposing non-universal GUT scale scalar masses consistent
with universality within SO(10) plus extra -term contributions associated
with the reduction in rank of the gauge symmetry group when SO(10)
spontaneously breaks to . We comment upon the
consequences of the sparticle mass spectrum for collider searches for
supersymmetry. One implication of SO(10) unification is that the light bottom
squark can be by far the lightest of the squarks. This motivates a dedicated
search for bottom squark pair production at and colliders.Comment: 12 page REVTEX file including 3 PS figures; revised manuscript
includes minor changes to coincide with published versio
Neutrino masses in lepton number violating mSUGRA
In SUSY models which violate R-parity, there exist trilinear lepton number
violating (LNV) operators which can lead to neutrino masses. If these operators
are defined at the unification scale, the renormalization group flow becomes
important and generally leads to one neutrino mass much heavier than the
others. We study, in a minimal supergravity (mSUGRA) set-up with two trilinear
LNV operators and three charged lepton mixing angles, numerically how these
parameters may be arranged to be compatible with neutrino oscillation data, and
discuss some phenomenological observations.Comment: 3 pages, 2 figures. Talk given at SUSY08. To be published in the
Conference Proceeding
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