57 research outputs found
Self-Tuning and de Sitter Brane Intersections in the 6-Dimensional Brane Models
We study the self-tuning of general brane junctions and brane networks on the
6-dimensional space-time. For the general brane junctions, there may exist one
fine-tuning among the brane tensions. For the brane networks, similar to the
5-dimensional self-tuning brane models, the brane tensions can be set
arbitrarily and there exists the singularity for the metric and bulk scalar.
And if we want to regularize the singularity, we will introduce the fine-tuning
among the brane tensions. In addition, because the 4-dimensional cosmological
constant we observe may be positive and very small, we discuss the brane
network with de Sitter brane intersections by introducing a bulk scalar.Comment: Latex, 11 page
Two component dark matter with multi-Higgs portals
With the assistance of two extra groups, i.e., an extra hidden gauge group
and a global group, we propose a two component dark matter
(DM) model. After the symmetry being broken, we obtain
both the vector and scalar DM candidates. The two DM candidates communicate
with the standard model (SM) via three Higgs as multi-Higgs portals. The three
Higgs are mixing states of the SM Higgs, the Higgs of the hidden sector and
real part of a supplement complex scalar singlet. We study relic density and
direct detection of DM in three scenarios. The resonance behaviors and
interplay between the two component DM candidates are represented through
investigating of the relic density in the parameter spaces of the two DMs
masses. The electroweak precision parameters constrains the two Higgs portals
couplings ( and ). The relevant vacuum stability and
naturalness problem in the parameter space of and are
studied as well. The model could alleviate these two problems in some parameter
spaces under the constraints of electroweak precision observables and Higgs
indirect search.Comment: 27 pages, 16 figures. Version accepted for publication in JHE
Top Hypercharge
We propose a top hypercharge model with gauge symmetry SU(3)_C x SU(2)_L x
U(1)_1 x U(1)_2 where the first two families of the Standard Model (SM)
fermions are charged under U(1)_1 while the third family is charged under
U(1)_2. The U(1)_1 x U(1)_2 gauge symmetry is broken down to the U(1)_Y gauge
symmetry, when a SM singlet Higgs field acquires a vacuum expectation value. We
consider the electroweak constraints, and compare the fit to experimental
observables to that of the SM. We study the quark CKM mixing between the first
two families and the third family, the neutrino masses and mixing, the flavour
changing neutral current effects in meson mixing and decays, the Z' discovery
potential at the Large Hadron Collider, the dark matter with a gauged Z_2
symmetry, and the Higgs boson masses.Comment: 17 pages and 4 figure
Probing the CP-even Higgs Sector via in the Natural NMSSM
After the discovery of a Standard Model (SM) like Higgs boson, naturalness
strongly favors the next to the Minimal Supersymmetric SM (NMSSM). In this
letter, we point out that the most natural NMSSM predicts the following CP-even
Higgs sector: (A) is the SM-like Higgs boson with mass
pushed-upward by a lighter with mass overwhelmingly within
; (B) GeV; (C)
has a significant coupling to top quarks and can decay to with a
large branching ratio. Using jet substructure we show that all the three Higgs
bosons can be discovered via at
the 14 TeV LHC. Especially, the LEP-LHC scenario with GeV has a
very good discovery potential.Comment: 5 pages, 2 figures. Some typos corrected and reference adde
Brane Networks in AdS Space
We present static solutions to Einstein's equations corresponding to the most
general network of orthogonal families of -branes in
-dimensional spacetimes. The bulk cosmological constant can take a
different value in each cell enclosed by intersecting branes and the extra
dimensions can be compact or noncompact. In each family of branes the
inter-brane spacing is arbitrary. The extra dimensions may be any or all of the
manifolds, , , and . Only when the extra
dimensions are or/and , can networks consisting solely of
positive tension branes be constructed. Such configurations may find
application in models with localized gravity and symmetry breaking by shining.Comment: Version to appear in PL
A Energy Balancing Control Strategy for Microgrid with Storage Systems
Abstract-In a microgrid, there is usually an energy storage system, while there is no continuous energy supply. The storage system does not only be used as a power supply in islanded state, but also could be taken as the demand side management devices in grid-connected state. In this paper, a system energy managing strategy is proposed. It can balance the energy in autonomous state, and manage power in gridconnected state under time-of-use pricing. Next, the droop control and economic dispatch method are introduced into the power management strategies to improve the power supply reliability and perform peak load shaving for maximum benefits. Finally, a simulation is shown to analyze the benefit from the strategies. And the applications of the economic dispatch method are discussed in the results under different operating conditions and market policies
Flipped SU (5)× UX (1) models from F-theory
We systematically construct flipped SU(5) X U(1)_X models without and with
bulk vector-like particles from F-theory. To realize the decoupling scenario,
we introduce sets of vector-like particles in complete SU(5) X U(1) multiplets
at the TeV scale, or at the intermediate scale, or at the TeV scale and high
scale. To avoid the Landau pole problem for the gauge couplings, we can only
introduce five sets of vector-like particles around the TeV scale. These
vector-like particles can couple to the Standard Model singlet fields, and
obtain suitable masses by Higgs mechanism. We study gauge coupling unification
in detail. We show that the U(1)_X flux contributions to the gauge couplings
preserve the SU(5) X U(1)_X gauge coupling unification. We calculate the
SU(3)_C X SU(2)_L unification scales, and the SU(5) X U(1)_X unification scales
and unified couplings. In most of our models, the high-scale or bulk
vector-like particles can be considered as string-scale threshold corrections
since their masses are close to the string scale. Futhermore, we discuss the
phenomenological consequences of our models. In particular, in the models with
TeV-scale vector-like particles, the vector-like particles can be observed at
the Large Hadron collider, the proton decay is within the reach of the future
Hyper-Kamiokande experiment, the lightest CP-even Higgs boson mass can be
increased, the hybrid inflation can be naturally realized, and the correct
cosmic primodial density fluctuations can be generated.Comment: RevTex4, 34 pages, 8 figures, 15 tables, version to appear in NP
An aggregator-based dynamic pricing mechanism and optimal scheduling scheme for the electric vehicle charging
High penetration of electric vehicles (EVs) in an uncontrolled manner could have disruptive impacts on the power grid, however, such impacts could be mitigated through an EV demand response program. The successful implementation of an efficient, effective, and aggregated demand response from EV charging depends on the incentive pricing mechanism and the load shifting protocols. In this study, a genetic algorithm-based multi-objective optimization model is developed to generate hourly dynamic Time-of-Use electricity tariffs and facilitate the decision making in load scheduling. As an illustrative example, a case study was carried out to examine the effect of applying demand response for EVs in Beijing, China. With the assumptions made, the maximum peak load can be reduced by 9.8% and the maximum customer savings for the EVs owners can reach 11.85%, compared to the business-as-usual case
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