187 research outputs found
AUTO-GENERATING MODELS FROM THEIR SEMANTICS AND CONSTRAINTS
poster abstractModel-Driven Engineering (MDE) facilitates building solutions in many en-terprise application domains through the systematic use of graphical lan-guages called domain-specific modeling languages (DSMLs). MDE tools, such as the Generic Modeling Environment (GME) and the Generic Eclipse Modeling System (GEMS), enable end-users to rapidly create such custom DSMLs. When DSMLs are coupled with constraint solvers, it is possible for DSML end-users to auto-generate solutions (i.e., models) based on the goals of the constraint solver (e.g., finding the optimal deployment for a set of software components given resource availability and resource needs). One requirement of using a constraint solver with a DSML, however, is that mod-elers have to create an initial model, also known as a âpartial modelâ. This implies that it is the end-users responsibility to (1) understand how to use the DSML and (2) understand when they have created an appropriate partial model that is a candidate for completion using a constraint solver.
Our research therefore focuses on addressing the two problems men-tioned above. We address the problems by analyzing the semantics and con-straints of the DSML (i.e., the meta-model). Based on our analysis, we then auto-generate as much of the model until we reach a point that requires us-er intervention. At that point, we present a set of operations (or moves) to the user and continue the process until the model is complete, or is solvable using a constraint solver
Unity of elementary particles and forces for the third family
We propose a non-supersymmetric SU(5) model in which only the third family of
fermions are unified. The model remedies the non-unification of the three
Standard Model couplings in non-supersymmetric SU(5). It also provides a
mechanism for baryon number violation which is needed for the baryon asymmetry
of the Universe and is not present in the Standard Model. Current experimental
constraints on the leptoquark gauge bosons, mediating such baryon and lepton
violating interactions in our model, allow their masses to be at the TeV scale.
These can be searched for as a (b\tau) or (tt) resonance at the Large Hadron
Collider as predicted in our model.Comment: Title changed, some changes in text and figures. Published in Phys.
Lett.
Hidden Gauge Symmetries: A New Possibility at the Colliders
We consider a new physics possibility at the colliders: the observation of
TeV scale massive vector bosons in the non-adjoint representations under the
Standard Model (SM) gauge symmetry. To have a unitary and renormalizable
theory, we propose a class of models with gauge symmetry where the SM fermions and Higgs fields
are singlets under the hidden gauge symmetry , and such massive
vector bosons appear after the gauge symmetry is spontaneously broken down to
the SM gauge symmetry. We discuss the model with SU(5) hidden gauge symmetry in
detail, and comment on the generic phenomenological implications.Comment: RevTex4, 5 pages, Discussions and References added, PLB versio
Unparticle Physics And Gauge Coupling Unification
Unparticle physics from a hidden conformal sector can alter the evolution of
the Standard Model (SM) gauge couplings via TeV scale threshold corrections. We
discuss how this may lead to gauge coupling unification at M_{GUT}\approx 2
\times 10^{15} GeV -- 5 \times 10^{17} GeV without introducing new particles in
the SM sector.Comment: 8 pages, 4 figure
Flavorful signatures at LHC and ILC
There are lots of new physics models which predict an extra neutral gauge
boson, referred as Z'-boson. In a certain class of these new physics models,
the Z'-boson has flavor-dependent couplings with the fermions in the Standard
Model (SM). Based on a simple model in which couplings of the SM fermions in
the third generation with the Z'-boson are different from those of the
corresponding fermions in the first two generations, we study the signatures of
Z'-boson at the Large Hadron Collider (LHC) and the International Linear
Collider (ILC). We show that at the LHC, the Z'-boson with mass around 1 TeV
can be produced through the Drell-Yan processes and its dilepton decay modes
provide us clean signatures not only for the resonant production of Z'-boson
but also for flavor-dependences of the production cross sections. We also study
fermion pair productions at the ILC involving the virtual Z'-boson exchange.
Even though the center-of-energy of the ILC is much lower than a Z'-boson mass,
the angular distributions and the forward-backward asymmetries of fermion pair
productions show not only sizable deviations from the SM predictions but also
significant flavor-dependences.Comment: 11 pages, 5 figures, some typos corrected, the version to appear in
PL
Phenomenology of the Top Mass in Realistic Extended Technicolor Models
Extended technicolor (ETC) theories typically require ETC gauge bosons
lighter than of order 1 TeV, to perturbatively generate the quark mass. We
point out that explicit models of mass splitting also typically contain
additional TeV scale ETC gauge bosons transforming in the {\it adjoint} of
technicolor, leading to large weak-isospin-breaking effects observable in the
parameter. Viable ETC models may thus require a lowest ETC scale of
order 10 TeV, with relatively strong and finely tuned couplings to generate
. Such models do not generate observable corrections to the
vertex.Comment: LaTex, 12 pages, including 2 EPS figures in 5 file
Axigluon as Possible Explanation for Forward-Backward Asymmetry
A flavor-nonuniversal chiral color model is introduced. It is used for
comparison to the recent data on . We concluded that
the data are consistent with interpretation as an axigluon exchange within
1 and a unique rise and fall behavior is predicated with regard to the
asymmetry as a function of invariant mass, which can
distinguish our model from others before one discovers the axigluon resonance.
Further aspects of the model are discussed.Comment: reference update
Higher Dimensional Operators and Low Energy Left-Right Symmetry
We consider higher dimensional operators due to quantum gravity or
spontaneous compactification of extra dimensions in Kaluza-Klein type theory
and their effect in the Lagrangian. These operators change the
boundary conditions at the unification scale. As a result one can allow
left-right symmetry to survive till very low energy (as low as TeV) for
a wide range of values for the coupling of these higher dimensional operators
and still make the theory compatible with the latest values of and derived from LEP. We consider both non-supersymmetric
and supersymmetric cases with standard higgses. Proton lifetime is very large
in these theories.Comment: LaTeX 6 pages,UH-511-765-9
Study of an Alternate Mechanism for the Origin of Fermion Generations
In usual extended technicolor (ETC) theories based on the group
, the quarks of charge 2/3 and -1/3 and the charged
leptons of all generations arise from ETC fermion multiplets transforming
according to the fundamental representation. Here we investigate a different
idea for the origin of SM fermion generations, in which quarks and charged
leptons of different generations arise from ETC fermions transforming according
to different representations of . Although this
mechanism would have the potential, {\it a priori}, to allow a reduction in the
value of relative to conventional ETC models, we show that, at least
in simple models, it is excluded by the fact that the technicolor sector is not
asymptotically free or by the appearance of fermions with exotic quantum
numbers which are not observed.Comment: 6 pages, late
Coloron Phenomenology
A flavor-universal extension of the strong interactions was recently proposed
in response to the apparent excess of high- jets in the inclusive jet
spectrum measured at the Tevatron. This paper studies the color octet of
massive gauge bosons (`colorons') that is present in the low-energy spectrum of
the model's Higgs phase. Constraints from searches for new particles decaying
to dijets and from measurements of the weak-interaction parameter imply
that the colorons must have masses greater than 870-1000 GeV. The implications
of recent Tevatron data and the prospective input from future experiments are
also discussed.Comment: 13 pages, 4 embedded Postscript figures, LaTeX, full postscript
version also available at http://smyrd.bu.edu/htfigs/htfigs.html rectified
confusing phrase at end of sub-section on 'dijets
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