3,717 research outputs found

    The extended BLMSSM with a 125 GeV Higgs boson and dark matter

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    To extend the BLMSSM, we not only add exotic Higgs superfields (ΦNL,φNL)(\Phi_{NL},\varphi_{NL}) to make the exotic lepton heavy, but also introduce the superfields(YY,Y′Y^\prime) 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 mh0m_{h^0} and the processes h0→γγh^0\rightarrow \gamma\gamma, h0→VV,V=(Z,W)h^0\rightarrow VV, V=(Z,W) 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 YY and Y′Y' mixing is also studied

    The order analysis for the two loop corrections to lepton MDM

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    The experimental data of the magnetic dipole moment(MDM) of lepton(ee, μ\mu) 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 MSHM_{SH} and MM with MSH≫MM_{SH}\gg M for supersymmetric particles. Squarks belong to MSHM_{SH} and the other supersymmetric particles belong to MM. 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 naturalness in the BLMSSM and B-LSSM

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    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 χ2\chi^2 analyses will be adopted in the BLMSSM and B-LSSM to calculate the Higgs mass, Higgs decays and muon g−2g-2. With the fine-tuning in the region 0.67%−2.5%0.67\%-2.5\% and 0.67%−5%0.67\%-5\%, 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 (χminBL)2=2.34736(\chi^{BL}_{min})^2 = 2.34736 and (χminB−L)2=2.47754(\chi^{B-L}_{min})^2 = 2.47754, respectively

    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

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    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

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    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 VL(t)=−VR(t)V_L(t)=-V_R(t) in two molecular structures: Al-C5{\rm C}_{5}-Al and Al-C60{\rm C}_{60}-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 t=0t=0 and t→∞t\rightarrow \infty.Comment: 15 pages, 8 figure
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