23 research outputs found
Patterns of consumption in a discrete choice model with asymmetric interactions
We study the consumption behaviour of an asymmetric network of heterogeneous agents in the framework of discrete choice models with stochastic decision rules. We assume that the interactions among agents are uniquely specified by their “social distance” and consumption is driven by peering, distinction and aspiration effects. The utility of each agent is positively or negatively affected by the choices of other agents and consumption is driven by peering, imitation and distinction effects. The dynamical properties of the model are explored, by numerical simulations, using three different evolution algorithms with: parallel, sequential and random-sequential updating rules. We analyze the long-time behaviour of the system which, given the asymmetric nature of the interactions, can either converge into a fixed point or a periodic attractor. We discuss the role of symmetric versus asymmetric contributions to the utility function and also that of idiosyncratic preferences, costs and memory in the consumption decision of the agents
Comment on "The Phenomenology of a Nonstandard Higgs Boson in W_L W_L Scattering"
We show that in Composite Higgs models, the coupling of the Higgs resonance
to a pair of bosons is weaker than the corresponding Standard Model
coupling, provided the Higgs arises from electroweak doublets only. This is
partly due to the effects of the nonlinear realization of the chiral symmetries
at the compositeness scale.Comment: 6 pages, BU-HEP 94-2
The Phase Diagram of the Sigma Model
We study the phase diagram of the scalar model in
dimensions. We find that the phase transition is of first order in most of the
parameter space. The theory can still be relevant to continuum physics (as an
effective theory) provided the transition is sufficiently weakly first order.
This places restrictions on the allowed coupling constants.Comment: 3 pages (Latex), 2 eps figures, uses espcrc2.sty, epsf, talk given at
LATTICE9
The phase diagram of the Sigma Model and its Implications for Chiral Hierarchies
Motivated by the issue of whether it is possible to construct
phenomenologically viable models where the electroweak symmetry breaking is
triggered by new physics at a scale , where is the
order parameter of the transition ( GeV) and is the scale
of new physics, we have studied the phase diagram of the
model. This is the relevant low energy effective theory for a class of models
which will be discussed below. We find that the phase transition in these
models is first order in most of parameter space. The order parameter can not
be made much smaller than the cut-off and, consequently a large hierarchy does
not appear sustainable. In the relatively small region in the space of
parameters where the phase transition is very weakly first order or second
order the model effectively reduces to the O(8) theory for which the triviality
considerations should apply.Comment: LaTeX file. 32 pages, 10 appended PostScript files, uses epsfig.st
Unitarity And Anomalous Top-Quark Yukawa Couplings
Unitarity constraints on anomalous top-Higgs couplings are examined. We also
compare the unitarity constraints with the constraints from electroweak
baryogenesis and electric dipole moments derived earlier.Comment: Iowa State University Preprint, AMES-HET 94-11, (Tex file) 10 pages,
one Figure available by reques
Minimal Composite Higgs Model with Light Bosons
We analyze a composite Higgs model with the minimal content that allows a
light Standard-Model-like Higgs boson, potentially just above the current LEP
limit. The Higgs boson is a bound state made up of the top quark and a heavy
vector-like quark. The model predicts that only one other bound state may be
lighter than the electroweak scale, namely a CP-odd neutral scalar. Several
other composite scalars are expected to have masses in the TeV range. If the
Higgs decay into a pair of CP-odd scalars is kinematically open, then this
decay mode is dominant, with important implications for Higgs searches. The
lower bound on the CP-odd scalar mass is loose, in some cases as low as
100 MeV, being set only by astrophysical constraints.Comment: 33 pages, latex. Corrections in eqs. 3.21, 3.23, 4.1, 4.5-10. One
figure adde
The profile of a nonstandard Higgs boson at the LHC
In a wide class of extensions of the Standard Model there is a scalar
resonance with the quantum numbers of the usual Higgs boson but with different
couplings to fermions and gauge bosons. Using an effective Lagrangian
description, we examine the phenomenology of such a generic nonstandard Higgs
boson at the LHC. In particular, we determine the circumstances under which
such a particle can be observed in its decay mode and distinguished from
the Higgs boson of the Standard Model. We briefly comment on the energy scale
effectively probed at the LHC, if the nonstandard nature of an observed Higgs
particle can be asserted.Comment: 21 pages, Latex, no figure
Unitary Standard Model from Spontaneous Dimensional Reduction and Weak Boson Scattering at the LHC
Spontaneous dimensional reduction (SDR) is a striking phenomenon predicted by
a number of quantum gravity approaches which all indicate that the spacetime
dimensions get reduced at high energies. In this work, we formulate an
effective theory of electroweak interactions based upon the standard model,
incorporating the spontaneous reduction of space-dimensions at TeV scale. The
electroweak gauge symmetry is nonlinearly realized with or without a Higgs
boson. We demonstrate that the SDR ensures good high energy behavior and
predicts unitary weak boson scattering. For a light Higgs boson of mass 125GeV,
the TeV-scale SDR gives a natural solution to the hierarchy problem. Such a
light Higgs boson can have induced anomalous gauge couplings from the TeV-scale
SDR. We find that the corresponding WW scattering cross sections become unitary
at TeV scale, but exhibit different behaviors from that of the 4d standard
model. These can be discriminated by the WW scattering experiments at the LHC.Comment: 38pp, Eur.Phys.J.(in Press); extended discussions for testing non-SM
Higgs boson(125GeV) via WW scattering; minor clarifications added; references
added; a concise companion is given in the short PLB letter arXiv:1301.457