4,029 research outputs found
The extended BLMSSM with a 125 GeV Higgs boson and dark matter
To extend the BLMSSM, we not only add exotic Higgs superfields
to make the exotic lepton heavy, but also introduce
the superfields(,) having couplings with lepton and exotic lepton
at tree level. The obtained model is called as EBLMSSM, which has difference
from BLMSSM especially for the exotic slepton(lepton) and exotic
sneutrino(neutrino). We deduce the mass matrices and the needed couplings in
this model. To confine the parameter space, the Higgs boson mass and
the processes , are
studied in the EBLMSSM. With the assumed parameter space, we obtain reasonable
numerical results according to data on Higgs from ATLAS and CMS. As a cold dark
mater candidate, the relic density for the lightest mass eigenstate of and
mixing is also studied
The naturalness in the BLMSSM and B-LSSM
In order to interpret the Higgs mass and its decays more naturally, we hope
to intrude the BLMSSM and B-LSSM. In the both models, the right-handed neutrino
superfields are introduced to better explain the neutrino mass problems. In
addition, there are other superfields considered to make these models more
natural than MSSM. In this paper, the method of analyses will be
adopted in the BLMSSM and B-LSSM to calculate the Higgs mass, Higgs decays and
muon . With the fine-tuning in the region and ,
we can obtain the reasonable theoretical values that are in accordance with the
experimental results respectively in the BLMSSM and B-LSSM. Meanwhile, the
best-fitted benchmark points in the BLMSSM and B-LSSM will be acquired at
minimal and ,
respectively
The order analysis for the two loop corrections to lepton MDM
The experimental data of the magnetic dipole moment(MDM) of lepton(,
) is very exact. The deviation between the experimental data and the
standard model prediction maybe come from new physics contribution.
In the supersymmetric models, there are very many two loop diagrams
contributing to the lepton MDM. In supersymmetric models, we suppose two mass
scales and with for supersymmetric particles.
Squarks belong to and the other supersymmetric particles belong to
. We analyze the order of the contributions from the two loop diagrams. The
two loop triangle diagrams corresponding to the two loop self-energy diagram
satisfy Ward-identity, and their contributions possess particular factors. This
work can help to distinguish the important two loop diagrams giving corrections
to lepton MDM.Comment: 12 pages, 3 figure
THE EFFECT OF PPARγ ACTIVATION BY PIOGLITAZONE ON THE LIPOPOLYSACCHARIDE-INDUCED PGE\u3csub\u3e2\u3c/sub\u3e AND NO PRODUCTION: POTENTIALUNDERLYING ALTERATION OF SIGNALING TRANSDUCTION
Microglia-mediated neuroinflammation plays an important role in the pathogenesis of Parkinson\u27s disease (PD). Uncontrolled microglia activation produces major proinflammatory factors including cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS) that may cause dopaminergic neurodegeneration. Peroxisome proliferator-activated receptor γ (PPARγ) agonist pioglitazone has potent antiinflammatory property. We hypothesize pioglitazone protects dopaminergic neuron from lipopolysaccharide (LPS)-induced neurotoxicity by interacting with relevant signal pathways, inhibiting microglial activation and decreasing inflammatory mediators.
First, the neuroprotection of pioglitazone was explored. Second, the signaling transductions such as jun N-terminal kinase (JNK) and the interference with these pathways by pioglitazone were investigated. Third, the effect of pioglitazone on these pathways-mediated PGE2 / nitric oxide (NO) generation was investigated. Finally, the effect of PPARγ antagonist on the inhibition of PGE2 / NO by pioglitazone was explored. The results show that LPS neurotoxicity is microglia-dependent, and pioglitazone protects neurons against LPS insult possibly by suppressing LPS-induced microglia activation and proliferation. Second, pioglitazone protects neurons from COX-2 / PGE2 mediated neuronal loss by interfering with the NF-κB and JNK, in PPARγ-independent mechanisms. Third, pioglitazone significantly inhibits LPS-induced iNOS / NO production, and inhibition of LPS-induced iNOS protects neuron. Fourth, inhibition p38 MAPK reduces LPS-induced NO generation but no effect is found upon JNK inhibition, and pioglitazone inhibits p38 MAPK phosphorylation induced by LPS. In addition, pioglitazone increases PPARγ phosphorylation, followed by the increased PI3K/Akt phosphorylation. Nevertheless, inhibition of PI3K increases LPS-induced p38 MAPK phosphorylation. Inhibition of PI3K eliminates the inhibitive effect of pioglitazone on the LPS-induced NO production, suggesting that the inhibitive effect of pioglitazone on the LPS-induced iNOS and NO might be PI3K-dependent
First-principles investigation of dynamical properties of molecular devices under a steplike pulse
We report a computationally tractable approach to first principles
investigation of time-dependent current of molecular devices under a step-like
pulse. For molecular devices, all the resonant states below Fermi level
contribute to the time-dependent current. Hence calculation beyond wideband
limit must be carried out for a quantitative analysis of transient dynamics of
molecules devices. Based on the exact non-equilibrium Green's function (NEGF)
formalism of calculating the transient current in Ref.\onlinecite{Maciejko}, we
develop two approximate schemes going beyond the wideband limit, they are all
suitable for first principles calculation using the NEGF combined with density
functional theory. Benchmark test has been done by comparing with the exact
solution of a single level quantum dot system. Good agreement has been reached
for two approximate schemes. As an application, we calculate the transient
current using the first approximated formula with opposite voltage
in two molecular structures: Al--Al and Al--Al. As illustrated in these examples, our formalism can be easily
implemented for real molecular devices. Importantly, our new formula has
captured the essential physics of dynamical properties of molecular devices and
gives the correct steady state current at and .Comment: 15 pages, 8 figure
26Al/10Be Age of Peking Man
The chronological position of Peking Man, or Homo erectus pekinensis, has long been pursued, but has remained problematic due to lack of a suitable dating method^1-7^. Here we report cosmogenic ^26^Al/ ^10^Be burial dating of quartz sediments and artifacts from the lower strata of Zhoukoudian Locality 1 where the remains of early members of the Peking Man family were discovered. This study marks the first radioisotopic dating of any early hominin site in China beyond the range of mass spectrometric U-series dating. The weighted mean of six meaningful measurements, 0.75 +/-; 0.09 (0.11) Ma (million years), provides the best age estimate for lower cultural Layers ^7-10^. Together with previously reported U-series^3^ and paleomagnetic^4^ data, as well as sedimentological considerations^8, 9^ these layers may be further correlated to S6-S7 in Chinese loess stratigraphy or marine isotope stages 17-18, in the range of ~0.68-0.75 Ma. These ages are substantially older than previously supposed and may imply hominin presence in northern China throughout early Middle Pleistocene climate cycles
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