34 research outputs found
Supersymmetric SU(3) X U(1) Gauge Model: Higgs Structure at the Electroweak Scale
We consider a supersymmetric version of the recently proposed SU(3) X U(1)
extended gauge model. We show that it is possible to have only two Higgs
doublets at the SU(2) X U(1) energy scale but they are not those of the minimal
supersymmetric standard model. In particular, the upper bound on the lightest
scalar boson of this model is at tree level and goes up
to 189 GeV after radiative corrections.Comment: 9 pages, Univ. of California, Riverside Report No. UCRHEP-T111, June
199
Efficient Coxian duration modelling for activity recognition in smart environment with the hidden semi-Markov model
In this paper, we exploit the discrete Coxian distribution and propose a novel form of stochastic model, termed as the Coxian hidden semi-Makov model (Cox-HSMM), and apply it to the task of recognising activities of daily living (ADLs) in a smart house environment. The use of the Coxian has several advantages over traditional parameterization (e.g. multinomial or continuous distributions) including the low number of free parameters needed, its computational efficiency, and the existing of closed-form solution. To further enrich the model in real-world applications, we also address the problem of handling missing observation for the proposed Cox-HSMM. In the domain of ADLs, we emphasize the importance of the duration information and model it via the Cox-HSMM. Our experimental results have shown the superiority of the Cox-HSMM in all cases when compared with the standard HMM. Our results have further shown that outstanding recognition accuracy can be achieved with relatively low number of phases required in the Coxian, thus making the Cox-HSMM particularly suitable in recognizing ADLs whose movement trajectories are typically very long in nature.<br /
Mutual cosideration of and in supersymmetric SO(10) grand unification
We compare the branching ratios for and
in terms of constraining the parameter space in
supersymmetric SO(10) grand unification models where supersymmetry is broken
softly near the Planck scale by generationally symmetric operators. We observe
two general cases. One with small and the other one with large
having third generation Yukawa coupling unification at the GUT
scale. \newline\indent We show that for small the branching ratio
constraints allow only a smaller region of parameter space for compared
to for gluino mass \alt 500 GeV.
With large , we find acceptable regions of parameter space with
\left|\mu \right|\alt 1 TeV only for . The dominant constraint on
large with parameter space is found to be given by the
branching ratio, while for large with it is found to be given by the branching ratio. In
many of these acceptable regions, we find that the
branching ratio is predicted to be within one order of magnitude of its current
experimental bound. We also show that the usually neglected gluino mediated
diagrams in can not be ignored in some regions of
parameter space, especially for large scenarios when the gluino
mass is near its lower experimental bound.Comment: 14 pages (Latex), 4 PS figs (uuencoded, epsf.tex), slight
modification in text, as to appear in Physics Letters
Sfermion masses in the supersymmetric economical 3-3-1 model
Sfermion masses and eigenstates in the supersymmetric economical 3-3-1 model
are studied. By lepton number conservation, the exotic squarks and
superpartners of ordinary quarks are decoupled. Due to the fact that in the
3-3-1 models, one generation of quarks behaves differently from other two, by
R-parity conservation, the mass mixing matrix of the squarks in this model are
smaller than that in the Minimal Supersymmetric Standard Model (MSSM). Assuming
substantial mixing in pairs of highest flavours, we are able to get mass
spectrum and eigenstates of all the sfermions. In the effective approximation,
the slepton mass splittings in the first two generations, are consistent with
those in the MSSM, namely: m^2_{\tilde{l}_L} - m^2_{\tilde{\nu}_{l L}} =
m_W^2 \cos 2\ga . In addition, within the above effective limit,
there exists degeneracy among sneutrinos in each multiplet:
. In contradiction to the
MSSM, the squark mass splittings are different for each generation and not to
be m_W^2 \cos 2\ga.Comment: 34 pages, 2 figures, Revised version in which D-term and F-term
contributions are slightly change
Neutrino masses through see-saw mechanism in 3-3-1 models
Some years ago it was shown by Ma that in the context of the electroweak
standard model there are, at the tree level, only three ways to generate small
neutrino masses by the see-saw mechanism via one effective dimension-five
operator. Here we extend this approach to 3-3-1 chiral models showing that in
this case there are several dimension-five operators and we also consider their
tree level realization.Comment: RevTex, 7 pages and 4 .eps figures. Version published in Phys. Rev.
D. with a change in the titl
Lepton masses in a supersymmetric 3-3-1 model
We consider the mass generation for both charginos and neutralinos in a 3-3-1
supersymmetric model. We show that R-parity breaking interactions leave the
electron and one of the neutrinos massless at the tree level. However the same
interactions induce masses for these particles at the 1-loop level. Unlike the
similar situation in the MSSM the masses of the neutralinos are related to the
masses of the charginos.Comment: RevTex, 11 pages incluing 2 .eps figures. Extended published versio
Explaining the Higgs Decays at the LHC with an Extended Electroweak Model
We show that the recent discovery of a new boson at the LHC, which we assume
to be a Higgs boson, and the observed enhancement in its diphoton decays
compared to the SM prediction, can be explained by a new doublet of charged
vector bosons from an extended electroweak gauge sector model with
SU(3)_C\otimesSU(3)_L\otimesU(1)_X symmetry. Our results show a good
agreement between our theoretical expected sensitivity to a 126--125 GeV Higgs
boson and the experimental significance observed in the diphoton channel at the
8 TeV LHC. Effects of an invisible decay channel for the Higgs boson are also
taken into account, in order to anticipate a possible confirmation of deficits
in the branching ratios into , , bottom quarks, and tau leptons.Comment: 16 pages, 5 figure
Seesaw tau lepton mass and calculable neutrino masses in a 3-3-1 model
In a version of the 3-3-1 model proposed by Duong and Ma the introduction of
the scalar sextet for giving mass to the charged leptons is avoided by adding a
singlet charged lepton. We show that in this case the lepton gains mass
through a seesaw--like mechanism. Besides we show how to generate neutrino
masses at the tree and at the 1-loop level with the respective
Maki-Nakagawa-Sakata leptonic mixing matrices.Comment: revtex, 5 pages and one eps figure. Published versio
Chromomagnetic Dipole Moment of the Top Quark Revisited
We study the complete one-loop contributions to the chromagnetic dipole
moment of the top quark in the Standard Model, two Higgs doublet
models, topcolor assited technicolor models (TC2), 331 models and extended
models with a single extra dimension. We find that the SM predicts
and that the predictions of the other models are also
consitent with the constraints imposed on by low-energy
precision measurements.Comment: 20 pages, 5 figures, Updat