1,777 research outputs found

    Exploring CP Violation in the MSSM

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    We explore the prospects for observing CP violation in the minimal supersymmetric extension of the Standard Model (MSSM) with six CP-violating parameters, three gaugino mass phases and three phases in trilinear soft supersymmetry-breaking parameters, using the CPsuperH code combined with a geometric approach to maximize CP-violating observables subject to the experimental upper bounds on electric dipole moments. We also implement CP-conserving constraints from Higgs physics, flavour physics and the upper limits on the cosmological dark matter density and spin-independent scattering. We study possible values of observables within the constrained MSSM (CMSSM), the non-universal Higgs model (NUHM), the CPX scenario and a variant of the phenomenological MSSM (pMSSM). We find values of the CP-violating asymmetry A_CP in b -> s gamma decay that may be as large as 3%, so future measurements of A_CP may provide independent information about CP violation in the MSSM. We find that CP-violating MSSM contributions to the B_s meson mass mixing term Delta M_Bs are in general below the present upper limit, which is dominated by theoretical uncertainties. If these could be reduced, Delta M_Bs could also provide an interesting and complementary constraint on the six CP-violating MSSM phases, enabling them all to be determined experimentally, in principle. We also find that CP violation in the h_{2,3} tau+ tau- and h_{2,3} tbar t couplings can be quite large, and so may offer interesting prospects for future pp, e+ e-, mu+ mu- and gamma gamma colliders.Comment: 36 pages, 32 figure

    Analysis, Design and Fabrication of centimeter-wave Dielectric Fresnel Zone Plate Lens and reflector

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    Fresnel lens has a long history in optics. This concept at non-optical wavelengths is also applicable. In this paper we report design and fabrication of a half and quarter wave dielectric Fresnel lens made of Plexiglas, and a Fresnel reflector at 11.1 GHz frequency. We made two lenses and one reflector at same frequency and compare their gain and radiation pattern to simulated results. Some methods for better focusing action will be introduced

    Group velocity control in the ultraviolet domain via interacting dark-state resonances

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    The propagation of a weak probe field in a laser-driven four-level atomic system is investigated. We choose mercury as our model system, where the probe transition is in the ultraviolet region. A high-resolution peak appears in the optical spectra due to the presence of interacting dark resonances. We show that this narrow peak leads to superluminal light propagation with strong absorption, and thus by itself is only of limited interest. But if in addition a weak incoherent pump field is applied to the probe transition, then the peak structure can be changed such that both sub- and superluminal light propagation or a negative group velocity can be achieved without absorption, controlled by the incoherent pumping strength

    Anomaly mediated SUSY breaking scenarios in the light of cosmology and in the dark (matter)

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    Anomaly mediation is a popular and well motivated supersymmetry breaking scenario. Different possible detailed realisations of this set-up are studied and actively searched for at colliders. Apart from limits coming from flavour, low energy physics and direct collider searches, these models are usually constrained by the requirement of reproducing the observations on dark matter density in the universe. We reanalyse these bounds and in particular we focus on the dark matter bounds both considering the standard cosmological model and alternative cosmological scenarios. These scenarios do not change the observable cosmology but relic dark matter density bounds strongly depend on them. We consider few benchmark points excluded by standard cosmology dark matter bounds and suggest that loosening the dark matter constraints is necessary in order to avoid a too strong (cosmological) model dependence in the limits that are obtained for these models. We also discuss briefly the implications for phenomenology and in particular at the Large Hadron Collider.Comment: 37 pages, 20 figures, 1 tabl

    Nonclassicality of induced coherence witnessed by contextuality

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    Quantum indistinguishability by path identity generates a new way of optical coherence, called ``induced coherence". The phenomenon, originally uncovered by Zou, Wang, and Mandel's experiment, is an emerging notion in modern quantum experiments with a wide range of implications. However, there has been controversy over its true quantum nature and whether the result can be emulated with classical light. We design a suitable contextuality test that can determine the conditions under which the setting produces distinguishing quantum predictions that cannot be described classically, namely, via the noncontextual hidden variable model.Comment: 12 pages, 7 figure

    Brief review of the searches for the rare decays Bs0μ+μB^0_s \rightarrow \mu^+ \mu^- and B0μ+μB^0 \rightarrow \mu^+ \mu^-

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    The current experimental status of the searches for the very rare decays Bs0μ+μB^0_s \rightarrow \mu^+ \mu^- and B0μ+μB^0 \rightarrow \mu^+ \mu^- is discussed. These channels are highly sensitive to various extensions of the Standard Model, specially in the scalar and pseudoscalar sector. The recent, most sensitive measurements from the CDF, ATLAS, CMS and LHCb collaborations are discussed and the combined upper exclusion limit on the branching fractions determined by the LHC experiments is shown to be 4.2×1094.2\times 10^{-9} for Bs0μ+μB^0_s \rightarrow \mu^+ \mu^- and 0.8×1090.8\times 10^{-9} for B0μ+μB^0 \rightarrow \mu^+ \mu^-. The implications of these tight bounds on a selected set of New Physics models is sketched.Comment: 20 pages, 15 figures, invited review for Modern Physics Letters

    Hydrodynamic instabilities in gaseous detonations: comparison of Euler, Navier–Stokes, and large-eddy simulation

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    A large-eddy simulation is conducted to investigate the transient structure of an unstable detonation wave in two dimensions and the evolution of intrinsic hydrodynamic instabilities. The dependency of the detonation structure on the grid resolution is investigated, and the structures obtained by large-eddy simulation are compared with the predictions from solving the Euler and Navier–Stokes equations directly. The results indicate that to predict irregular detonation structures in agreement with experimental observations the vorticity generation and dissipation in small scale structures should be taken into account. Thus, large-eddy simulation with high grid resolution is required. In a low grid resolution scenario, in which numerical diffusion dominates, the structures obtained by solving the Euler or Navier–Stokes equations and large-eddy simulation are qualitatively similar. When high grid resolution is employed, the detonation structures obtained by solving the Euler or Navier–Stokes equations directly are roughly similar yet equally in disagreement with the experimental results. For high grid resolution, only the large-eddy simulation predicts detonation substructures correctly, a fact that is attributed to the increased dissipation provided by the subgrid scale model. Specific to the investigated configuration, major differences are observed in the occurrence of unreacted gas pockets in the high-resolution Euler and Navier–Stokes computations, which appear to be fully combusted when large-eddy simulation is employed

    Contribution of Blastocystishominis subtypes and associated inflammatory factors in development of irritable bowel syndrome

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    Blastocystis hominis with worldwide distribution is a human intestinal protozoa found in all countries. There have been differences in the severity of the pathogenesis of various Blastocystis spp. and a concomitant variation in the plasma concentration of the cytokines in patients with irritable bowel syndrome. In the present study, we aimed to demonstrate the contribution of B. hominis subtypes in the development of irritable bowel syndrome. Stool samples were collected from patients with gastrointestinal disorders. All samples were evaluated through native-lugol method. Total DNA was extracted. A PCR protocol was developed to amplify a specific region of the SSU ribosomal DNA (rDNA) gene. Serum levels of IL-6 and TNF-alpha were determined by immunoassay methods. The ClustalW algorithm was applied to align and blast the nucleotide sequences of the amplified region of the SSU rDNA gene. To evaluate the phylogenetic and molecular evolutionary of the nucleotide sequences, we used the MEGA software. In this study, we found 26 haplotypes of B. hominis in the studied samples which were collectively belong to five subtypes (ST1, ST2 in patients without irritable bowel syndrome vs. ST3 and two unknown subtypes in patients with irritable bowel syndrome). Result of ELISA showed a high level of IL-6 and TNF-alpha in the serum of patients with irritable bowel syndrome. The genetic heterogeneity of B. hominis and the existence of different subtypes of the protozoan in patients with IBS may shed light to the fact that some subtypes of parasites may involve in the pathogenesis of IBS

    Contribution of Blastocystishominis subtypes and associated inflammatory factors in development of irritable bowel syndrome

    Get PDF
    Blastocystis hominis with worldwide distribution is a human intestinal protozoa found in all countries. There have been differences in the severity of the pathogenesis of various Blastocystis spp. and a concomitant variation in the plasma concentration of the cytokines in patients with irritable bowel syndrome. In the present study, we aimed to demonstrate the contribution of B. hominis subtypes in the development of irritable bowel syndrome. Stool samples were collected from patients with gastrointestinal disorders. All samples were evaluated through native-lugol method. Total DNA was extracted. A PCR protocol was developed to amplify a specific region of the SSU ribosomal DNA (rDNA) gene. Serum levels of IL-6 and TNF-alpha were determined by immunoassay methods. The ClustalW algorithm was applied to align and blast the nucleotide sequences of the amplified region of the SSU rDNA gene. To evaluate the phylogenetic and molecular evolutionary of the nucleotide sequences, we used the MEGA software. In this study, we found 26 haplotypes of B. hominis in the studied samples which were collectively belong to five subtypes (ST1, ST2 in patients without irritable bowel syndrome vs. ST3 and two unknown subtypes in patients with irritable bowel syndrome). Result of ELISA showed a high level of IL-6 and TNF-alpha in the serum of patients with irritable bowel syndrome. The genetic heterogeneity of B. hominis and the existence of different subtypes of the protozoan in patients with IBS may shed light to the fact that some subtypes of parasites may involve in the pathogenesis of IBS

    Evaluation of apoptosis and angiogenesis in ectopic and eutopic stromal cells of patients with endometriosis compared to non-endometriotic controls

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    Background: Endometriosis is a chronic, painful, and inflammatory disease characterized by extra-uterine growth of endometrial tissues. Increased angiogenesis and resistance to apoptosis have been suggested to be involved in pathogenesis and development of endometriosis. The objective of this study was to examine apoptosis potential and angiogenesis contribution of eutopic (EuESCs) and ectopic (EESCs) endometrial stromal cells in patients with endometriosis compared to endometrial stromal cells from non-endometriotic controls (CESCs). Methods: Stromal cells were isolated by enzymatic digestion of ectopic (n = 11) and eutopic (n = 17) endometrial tissues from laparoscopically-confirmed endometriotic patients. Endometrial stromal cells of 15 non-endometriotic patients served as control. Following cell characterization by immunofluorescent staining and flow cytometry using a panel of antibodies, the total RNA was isolated from the cultured cells, and analyzed for the expression of genes involved in apoptosis (Bcl-2, Bcl-xL, Bax, and caspase-3) and angiogenesis vascular endothelial growth factor-A (VEGF-A) and hepatocyte growth factor (HGF) by Real-time PCR. Results: Significantly higher gene expression levels of Bcl-2 and Bcl-xL were found in EESCs compared with EuESCs and CESCs (p < 0.01). The gene expression of Bax in EESCs, EuESCs, and CESCs was not statistically significant. Furthermore, EuESCs exhibited a significantly lower caspase-3 gene expression compared with CESCs (p < 0.01) or EESCs (p < 0.05). Regarding angiogenesis, VEGF-A gene expression in EESCs (p < 0.001) and EuESCs (p < 0.05) were significantly higher compared with those of CESCs. EESCs exhibited a significantly higher HGF gene expression compared with EuESCs (p < 0.05). Conclusions: These findings suggest reduced propensity to apoptosis and increased angiogenesis potential of EESCs, which may be involved in pathogenesis of endometriosis. © 2020 The Author(s)
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