1,146 research outputs found
A Peculiar Dynamically Warped Theory Space
We study a supersymmetric deconstructed gauge theory in which a warp factor
emerges dynamically, driven by Fayet-Iliopoulos terms. The model is peculiar in
that it possesses a global supersymmetry that remains unbroken despite
nonvanishing D-term vacuum expectation values. Inclusion of gravity and/or
additional messenger fields leads to the collective breaking of supersymmetry
and to an unusual phenomenology.Comment: 4 pages LaTeX, Presented at SUSY06, the 14th International Conference
on Supersymmetry and the Unification of Fundamental Interactions, Irvine,
California, USA 12-17 June 200
Electroweak Constraints on Extended Models with Extra Dimensions
Electroweak measurements place significant bounds on higher-dimensional
versions of the standard model in which the gauge and Higgs fields have
Kaluza-Klein excitations. These bounds may be altered quantitatively if chiral
matter is also allowed to propagate in the higher-dimensional `bulk'. We
determine the electroweak constraints on a number of models of this type,
including scenarios in which only the leptons or only the first two generations
of matter fields propagate in the bulk. We also consider the possibility that
different factors of the electroweak gauge group may be distinguished by their
bulk/three-brane assignment, and study a minimal extra-dimensional Z' model. We
find typical bounds on the compactification scale between 1.5 and 4 TeV, and
comment on models in which these bounds might be significantly relaxed.Comment: 15 pages Revtex, 1 EPS figur
Pseudo-Familon Dark Matter
Motivated by a model of pseudo-Majoron dark matter, we show how the breaking
of a global symmetry that acts nontrivially in lepton generation space can lead
to a viable pseudo-familon dark matter candidate. Unlike the pseudo-Majoron,
the pseudo-familon in our model decays primarily to charged leptons and can
account for the excess observed in the cosmic ray electron and positron
spectra.Comment: 12 pages LaTeX, 1 figur
Orbitally Excited Baryons in Large N_c QCD
We present a model-independent analysis of the mass spectrum of nonstrange
l=1 baryons in large N_c QCD. The 1/N_c expansion is used to select and order a
basis of effective operators that spans the nine observables (seven masses and
two mixing angles). Comparison to the data provides support for the validity of
the 1/N_c expansion, but also reveals that only a few nontrivial operators are
strongly preferred. We show that our results have a consistent interpretation
in a constituent quark model with pseudoscalar meson exchange interactions.Comment: 4 pages LaTeX. Invited parallel session talk presented at the XVth
Particles and Nuclei International Conference (PANIC99), June 10, 1999,
Uppsala, Swede
Bosonic Topcolor
A topcolor model is presented that contains both composite and fundamental
scalar fields. Strong dynamics accounts for most of the top quark mass and part
of the electroweak symmetry breaking scale. The fundamental scalar is weakly
coupled and transmits its share of electroweak symmetry breaking to the light
fermions. The model is allowed by the current experimental bounds, and can give
a potentially large contribution to mixing.Comment: Talk given by A. Aranda at DPF 2000, Ohio State, August 200
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