5,376 research outputs found
Towards the fate of natural composite Higgs model through single search at the 8 TeV LHC
We analyze the observational potential of single production in both the
and decay channels at 8 TeV
LHC using an integrated luminosity of 25 . Our analysis is
based on a simplified model with minimal coset in which the
is a singlet of the unbroken SO(4). The single production, as a
consequence of electroweak symmetry breaking, is less kinematically suppressed,
associated with a light forward jet and has boosted decay products at the 8 TeV
LHC. Therefore it provides the most promising channel in searching for a heavy
. We have exploited the above kinematical features and used the jet
substructure method to reconstruct the boosted Higgs in decay channel. It
is shown that a strong constraint on the coupling () at the 95% C. L. can be obtained for GeV.Comment: 22 pages, 8 figures, 5 tables, refs added in v
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
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
Type-III two Higgs doublet model plus a pseudoscalar confronted with , muon and dark matter
In this work, we introduce an extra singlet pseudoscalar into the Type-III
two Higgs doublet model (2HDM) which is supposed to solve a series of problems
in the modern particle-cosmology. With existence of a light pseudoscalar, the
excess measured at CMS and as well as the
anomaly could be simultaneously explained within certain parameter spaces that
can also tolerate the data on the flavor-violating processes
and Higgs decay gained at LHC. Within the same
parameter spaces, the DM relic abundance is well accounted. Moreover, the
recently observed Galactic Center gamma ray excess(GCE) is proposed to realize
through dark matter(DM) pair annihilations, and in this work, the scenario of
the annihilation being mediated by the pseudoscalar is also addressed.Comment: 14 pages, 8 figures, version to appear in NP
Electron Flavored Dark Matter
In this paper we investigate the phenomenology of the electron flavored Dirac
dark matter with two types of portal interactions. We analyze constraints from
the electron magnetic moment anomaly, LHC searches of singly charged scalar,
dark matter relic abundance as well as direct and indirect detections. Our
study shows that the available parameter space is quite constrained, but there
are parameter space that is compatible with the current data. We further show
that the DAMPE cosmic ray electron excess, which indicates cosmic ray excess at
around 1.5 TeV, can be interpreted as the annihilation of dark matter into
electron positron pairs in this model.Comment: 6 pages, 5 figure
Genetic learning particle swarm optimization
Social learning in particle swarm optimization (PSO) helps collective efficiency, whereas individual reproduction in genetic algorithm (GA) facilitates global effectiveness. This observation recently leads to hybridizing PSO with GA for performance enhancement. However, existing work uses a mechanistic parallel superposition and research has shown that construction of superior exemplars in PSO is more effective. Hence, this paper first develops a new framework so as to organically hybridize PSO with another optimization technique for “learning.” This leads to a generalized “learning PSO” paradigm, the *L-PSO. The paradigm is composed of two cascading layers, the first for exemplar generation and the second for particle updates as per a normal PSO algorithm. Using genetic evolution to breed promising exemplars for PSO, a specific novel *L-PSO algorithm is proposed in the paper, termed genetic learning PSO (GL-PSO). In particular, genetic operators are used to generate exemplars from which particles learn and, in turn, historical search information of particles provides guidance to the evolution of the exemplars. By performing crossover, mutation, and selection on the historical information of particles, the constructed exemplars are not only well diversified, but also high qualified. Under such guidance, the global search ability and search efficiency of PSO are both enhanced. The proposed GL-PSO is tested on 42 benchmark functions widely adopted in the literature. Experimental results verify the effectiveness, efficiency, robustness, and scalability of the GL-PSO
A WENO Algorithm of the Temperature and Ionization Profiles around a Point Source
We develop a numerical solver for radiative transfer problems based on the
weighted essentially nonoscillatory (WENO) scheme modified with anti-diffusive
flux corrections, in order to solve the temperature and ionization profiles
around a point source of photons in the reionization epoch. Algorithms for such
simulation must be able to handle the following two features: 1. the sharp
profiles of ionization and temperature at the ionizing front (I-front) and the
heating front (T-front), and 2. the fraction of neutral hydrogen within the
ionized sphere is extremely small due to the stiffness of the rate equations of
atom processes. The WENO scheme can properly handle these two features, as it
has been shown to have high order of accuracy and good convergence in capturing
discontinuities and complicated structures in fluid as well as to be
significantly superior over piecewise smooth solutions containing
discontinuities. With this algorithm, we show the time-dependence of the
preheated shell around a UV photon source. In the first stage the I-front and
T-front are coincident, and propagate with almost the speed of light. In later
stage, when the frequency spectrum of UV photons is hardened, the speeds of
propagation of the ionizing and heating fronts are both significantly less than
the speed of light, and the heating front is always beyond the ionizing front.
In the spherical shell between the I- and T-fronts, the IGM is heated, while
atoms keep almost neutral. The time scale of the preheated shell evolution is
dependent on the intensity of the photon source. We also find that the details
of the pre-heated shell and the distribution of neutral hydrogen remained in
the ionized sphere are actually sensitive to the parameters used. The WENO
algorithm can provide stable and robust solutions to study these details.Comment: 24 pages, 7 figures, accepted in New Astronom
Poly[aqua[μ3-4-carboxy-2-(pyridin-4-yl)-1H-imidazole-5-carboxylato-κ5 N 1,O 5:N 3,O 4:N 2]nickel(II)]
The water-coordinated Ni2+ cation in the title compound, [Ni(C10H5N3O4)(H2O)]n, assumes an octahedral NiN3O3 coordination mode and is N,O-chelated by two deprotonated 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid (HPyImDC2−) ligands, forming a layer structure extending in the bc plane. The chains are arranged along the b-axis direction, forming a layer structure extending in the bc plane. O—H⋯O hydrogen bonding between the layers results in the formation of a three-dimensional supramolecular framework. The structure is isotypic with the Zn analogue [Li et al. (2009). Cryst. Growth Des.
6, 3423–3431]
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