45,559 research outputs found
New Lepton Family Symmetry and Neutrino Tribimaximal Mixing
The newly proposed finite symmetry Sigma(81) is applied to the problem of
neutrino tribimaximal mixing. The result is more satisfactory than those of
previous models based on A_4 in that the use of auxiliary symmetries (or
mechanisms) may be avoided. Deviations from the tribimaximal pattern are
expected, but because of its basic structure, only tan^2 (theta_12) may differ
significantly from 0.5 (say 0.45) with sin^2 (2 theta_23) remaining very close
to one, and theta_13 very nearly zero.Comment: 8 pages, no figur
Centers and Cocenters of -Hecke algebras
In this paper, we give explicit descriptions of the centers and cocenters of
-Hecke algebras associated to finite Coxeter groups.Comment: 13 pages, a mistake in 4.2 is correcte
Flavor changing Z' couplings at the LHC
Models with a non-universal Z' exhibit in general flavor changing neutral
currents (FCNC) at tree-level. When the Z' couplings favor the third
generation, flavor changing transitions of the form Z'tc and Z'tu could be
large enough to be observable at the LHC. In this paper we explore this
possibility using the associated production of a single top-quark with the Z'
and find that integrated luminosities of a few hundred fb are necessary
to probe the interesting region of parameter space.Comment: 12 LaTeX Pages, 10 EPS Figure
Energy-Conserving Lattice Boltzmann Thermal Model in Two Dimensions
A discrete velocity model is presented for lattice Boltzmann thermal fluid dynamics.
This model is implemented and tested in two dimensions with a finite difference scheme. Comparison with analytical solutions shows an excellent agreement even for wide temperature differences. An alternative approximate approach is then presented for traditional lattice transport schemes
Invisible Higgs boson, continuous mass fields and unHiggs mechanism
We explore the consequences of an electroweak symmetry breaking sector which
exhibits approximately scale invariant dynamics -- i.e., nontrivial fixed point
behavior, as in unparticle models. One can think of an unHiggs as a composite
Higgs boson with a continuous mass distribution. We find it convenient to
represent the unHiggs in terms of a Kallen-Lehmann spectral function, from
which it is simple to verify the generation of gauge boson and fermion masses,
and unitarization of WW scattering. We show that a spectral function with broad
support, which corresponds to approximate fixed point behavior over an extended
range of energy, can lead to an effectively invisible Higgs particle, whose
decays at LEP or LHC could be obscured by background.Comment: 8 page
Suitability of A_4 as a Family Symmetry in Grand Unification
In the recent successful applications of the non-Abelian discrete symmetry
A_4 to the tribimaximal mixing of neutrinos, lepton doublets and singlets do
not transform in the same way. It appears thus to be unsuitable as a family
symmetry in grand unification. A simple resolution of this dilemma is proposed.Comment: 6 pages, no figur
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Filtering for networked stochastic time-delay systems with sector nonlinearity
Copyright [2009] IEEE. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.This paper is concerned with the filtering problem for a class of discrete-time stochastic nonlinear networked control systems with network-induced incomplete measurements. The incomplete measurements include both the multiple random communication delays and random packet losses, which are modeled by a unified stochastic expression in terms of a set of indicator functions that is dependent on certain stochastic variable. The nonlinear functions are assumed to satisfy the sector nonlinearities. The purpose of the addressed filtering problem is to design a linear filter such that the filtering-error dynamics is exponentially mean-square stable. By using the linear-matrix-inequality (LMI) method and delay-dependent technique, sufficient conditions are derived which are dependent on the occurrence probability of both the random communication delays and missing measurement. The filter gain is then characterized by the solution to a set of LMIs. A simulation example is exploited to demonstrate the effectiveness of the proposed design procedures
Lepton flavor violating Higgs decays and unparticle physics
We predict the branching ratios of the lepton flavor violating Higgs decays
H^0->e^{\pm} \mu^{\pm}, H^0-> e^{\pm} \tau^{\pm} and H^0->\mu^{\pm} \tau^{\pm}
in the case that the lepton flavor violation is carried by the scalar
unparticle mediation. We observe that their branching ratios are strongly
sensitive to the unparticle scaling dimension and they can reach to the values
of the order of , for the heavy lepton flavor case and for the small
values of the scaling dimension.Comment: 12 pages, 7 Figures, 1 Table
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