16 research outputs found

    Spin and Chirality Effects in Antler-Topology Processes at High Energy e+eβˆ’e^+e^- Colliders

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    We perform a model-independent investigation of spin and chirality correlation effects in the antler-topology processes e+eβˆ’β†’P+Pβˆ’β†’(β„“+D0)(β„“βˆ’DΛ‰0)e^+e^-\to\mathcal{P}^+\mathcal{P}^-\to (\ell^+ \mathcal{D}^0) (\ell^-\mathcal{\bar{D}}^0) at high energy e+eβˆ’e^+e^- colliders with polarized beams. Generally the production process e+eβˆ’β†’P+Pβˆ’e^+e^-\to\mathcal{P}^+\mathcal{P}^- can occur not only through the ss-channel exchange of vector bosons, V0\mathcal{V}^0, including the neutral Standard Model (SM) gauge bosons, Ξ³\gamma and ZZ, but also through the ss- and tt-channel exchanges of new neutral states, S0\mathcal{S}^0 and T0\mathcal{T}^0, and the uu-channel exchange of new doubly-charged states, Uβˆ’βˆ’\mathcal{U}^{--}. The general set of (non-chiral) three-point couplings of the new particles and leptons allowed in a renormalizable quantum field theory is considered. The general spin and chirality analysis is based on the threshold behavior of the excitation curves for P+Pβˆ’\mathcal{P}^+\mathcal{P}^- pair production in e+eβˆ’e^+e^- collisions with longitudinal and transverse polarized beams, the angular distributions in the production process and also the production-decay angular correlations. In the first step, we present the observables in the helicity formalism. Subsequently, we show how a set of observables can be designed for determining the spins and chiral structures of the new particles without any model assumptions. Finally, taking into account a typical set of approximately chiral invariant scenarios, we demonstrate how the spin and chirality effects can be probed experimentally at a high energy e+eβˆ’e^+e^- collider.Comment: 50 pages, 14 figures, 6 tables, matches version published in EPJ

    Activation of Sirt1 by Resveratrol Inhibits TNF-Ξ± Induced Inflammation in Fibroblasts

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    Inflammation is one of main mechanisms of autoimmune disorders and a common feature of most diseases. Appropriate suppression of inflammation is a key resolution to treat the diseases. Sirtuin1 (Sirt1) has been shown to play a role in regulation of inflammation. Resveratrol, a potent Sirt1 activator, has anti-inflammation property. However, the detailed mechanism is not fully understood. In this study, we investigated the anti-inflammation role of Sirt1 in NIH/3T3 fibroblast cell line. Upregulation of matrix metalloproteinases 9 (MMP-9), interleukin-1beta (IL-1Ξ²), IL-6 and inducible nitric oxide synthase (iNOS) were induced by tumor necrosis factor alpha (TNF-Ξ±) in 3T3 cells and resveratrol suppressed overexpression of these pro-inflammatory molecules in a dose-dependent manner. Knockdown of Sirt1 by RNA interference caused 3T3 cells susceptible to TNF-Ξ± stimulation and diminished anti-inflammatory effect of resveratrol. We also explored potential anti-inflammatory mechanisms of resveratrol. Resveratrol reduced NF-ΞΊB subunit RelA/p65 acetylation, which is notably Sirt1 dependent. Resveratrol also attenuated phosphorylation of mammalian target of rapamycin (mTOR) and S6 ribosomal protein (S6RP) while ameliorating inflammation. Our data demonstrate that resveratrol inhibits TNF-Ξ±-induced inflammation via Sirt1. It suggests that Sirt1 is an efficient target for regulation of inflammation. This study provides insight on treatment of inflammation-related diseases

    The Physics of the B Factories

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    This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C
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