9,675 research outputs found

    Collider Interplay for Supersymmetry, Higgs and Dark Matter

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    We discuss the potential impacts on the CMSSM of future LHC runs and possible electron-positron and higher-energy proton-proton colliders, considering searches for supersymmetry via MET events, precision electroweak physics, Higgs measurements and dark matter searches. We validate and present estimates of the physics reach for exclusion or discovery of supersymmetry via MET searches at the LHC, which should cover the low-mass regions of the CMSSM parameter space favoured in a recent global analysis. As we illustrate with a low-mass benchmark point, a discovery would make possible accurate LHC measurements of sparticle masses using the MT2 variable, which could be combined with cross-section and other measurements to constrain the gluino, squark and stop masses and hence the soft supersymmetry-breaking parameters m_0, m_{1/2} and A_0 of the CMSSM. Slepton measurements at CLIC would enable m_0 and m_{1/2} to be determined with high precision. If supersymmetry is indeed discovered in the low-mass region, precision electroweak and Higgs measurements with a future circular electron-positron collider (FCC-ee, also known as TLEP) combined with LHC measurements would provide tests of the CMSSM at the loop level. If supersymmetry is not discovered at the LHC, is likely to lie somewhere along a focus-point, stop coannihilation strip or direct-channel A/H resonance funnel. We discuss the prospects for discovering supersymmetry along these strips at a future circular proton-proton collider such as FCC-hh. Illustrative benchmark points on these strips indicate that also in this case FCC-ee could provide tests of the CMSSM at the loop level.Comment: 47 pages, 26 figure

    Constitutively active acetylcholine-dependent potassium current increases atrial defibrillation threshold by favoring post-shock re-initiation

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    Electrical cardioversion (ECV), a mainstay in atrial fibrillation (AF) treatment, is unsuccessful in up to 10-20% of patients. An important aspect of the remodeling process caused by AF is the constitutive activition of the atrium-specific acetylcholine-dependent potassium current (I-K,I-ACh -> I-K,I-ACh-c), which is associated with ECV failure. This study investigated the role of I-K,I-ACh-c in ECV failure and setting the atrial defibrillation threshold (aDFT) in optically mapped neonatal rat cardiomyocyte monolayers. AF was induced by burst pacing followed by application of biphasic shocks of 25-100 V to determine aDFT. Blocking I-K,I-ACh-c by tertiapin significantly decreased DFT, which correlated with a significant increase in wavelength during reentry. Genetic knockdown experiments, using lentiviral vectors encoding a Kcnj5-specific shRNA to modulate I-K,I-ACh-c, yielded similar results. Mechanistically, failed ECV was attributed to incomplete phase singularity (PS) removal or reemergence of PSs (i.e. re-initiation) through unidirectional propagation of shock-induced action potentials. Re-initiation occurred at significantly higher voltages than incomplete PS-removal and was inhibited by I-K,I-ACh-c blockade. Whole-heart mapping confirmed our findings showing a 60% increase in ECV success rate after I-K,I-ACh-c blockade. This study provides new mechanistic insight into failing ECV of AF and identifies I-K,I-ACh-c as possible atrium-specific target to increase ECV effectiveness, while decreasing its harmfulness

    Genetic-variability within and between populations of 2 species of racopilum (racopilaceae, bryopsida)

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    Genetic variability in three populations of Racopilum spectabile and two populations of R. cuspidigerum was estimated by horizontal polyacrylamide electrophoresis. Eight of 22 tested enzyme systems were scorable; they represented 10 loci. The fraction of polymorphic loci in the most variable populations was 0.64 in R. spectabile and 0.55 in R. cuspidigerum. Estimates of gene diversity were 0.26 for both species, which is a high level of genetic variability compared with phanerogams. The genetic distance was positively correlated with spatial distance. Differences in allozyme frequencies between R. cuspidigerum and R. spectabile were considerably larger than differences within each species. One of the populations of R. cuspidigerum lacked genetic variability, which might be caused by asexual propagation. Maintenance of genetic variation within and origin of differentiation between populations are discussed. Our results reinforce the view that the diplohaplontic Bryophytina possess an evolutionary potential comparable with that of phanerogam

    Compact, low power and low threshold electrically pumped micro disc lasers for 20Gb/s non return to zero all optical wavelength conversion

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    \u3cp\u3eUsing a 7.5μm wide InP Micro-Disc-Laser, with a very low ∼100μA threshold current, heterogeneously integrated on top of Silicon on Insulator substrate, all optical NRZ wavelength conversion at speeds up to 20Gb/s is demonstrated.\u3c/p\u3

    A new limit on the Ultra-High-Energy Cosmic-Ray flux with the Westerbork Synthesis Radio Telescope

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    A particle cascade (shower) in a dielectric, for example as initiated by an ultra-high energy cosmic ray, will have an excess of electrons which will emit coherent \v{C}erenkov radiation, known as the Askaryan effect. In this work we study the case in which such a particle shower occurs in a medium just below its surface. We show, for the first time, that the radiation transmitted through the surface is independent of the depth of the shower below the surface when observed from far away, apart from trivial absorption effects. As a direct application we use the recent results of the NuMoon project, where a limit on the neutrino flux for energies above 102210^{22}\,eV was set using the Westerbork Synthesis Radio Telescope by measuring pulsed radio emission from the Moon, to set a limit on the flux of ultra-high-energy cosmic rays.Comment: Accepted for publication in Phys. Rev.

    Implications of Improved Higgs Mass Calculations for Supersymmetric Models

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    We discuss the allowed parameter spaces of supersymmetric scenarios in light of improved Higgs mass predictions provided by FeynHiggs 2.10.0. The Higgs mass predictions combine Feynman-diagrammatic results with a resummation of leading and subleading logarithmic corrections from the stop/top sector, which yield a significant improvement in the region of large stop masses. Scans in the pMSSM parameter space show that, for given values of the soft supersymmetry-breaking parameters, the new logarithmic contributions beyond the two-loop order implemented in FeynHiggs tend to give larger values of the light CP-even Higgs mass, M_h, in the region of large stop masses than previous predictions that were based on a fixed-order Feynman-diagrammatic result, though the differences are generally consistent with the previous estimates of theoretical uncertainties. We re-analyze the parameter spaces of the CMSSM, NUHM1 and NUHM2, taking into account also the constraints from CMS and LHCb measurements of B_s to \mu+\mu- and ATLAS searches for MET events using 20/fb of LHC data at 8 TeV. Within the CMSSM, the Higgs mass constraint disfavours tan beta lesssim 10, though not in the NUHM1 or NUHM2.Comment: 22 pages, 17 figure
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