9,675 research outputs found
Collider Interplay for Supersymmetry, Higgs and Dark Matter
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
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)
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
Genetic-variability within and between populations of 2 species of racopilum (racopilaceae, bryopsida)
Compact, low power and low threshold electrically pumped micro disc lasers for 20Gb/s non return to zero all optical wavelength conversion
\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
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 \,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
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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