62,617 research outputs found

    Electrophysiological Mechanisms of Atrial Flutter

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    Atrial flutter (AFL) is a common arrhythmia in clinical practice. Several experimental models such as tricuspid regurgitation model, tricuspid ring model, sterile pericarditis model and atrial crush injury model have provided important information about reentrant circuit and can test the effect of antiarrhythmic drugs. Human atrial flutter has typical and atypical forms. Typical atrial flutter rotates around tricuspid annulus and uses the crista terminalis and sometimes sinus venosa as the boundary. The IVC-tricuspid isthmus is a slow conduction zone and the target of radiofrequency ablation. Atypical atrial flutter may arise from the right or left atrium. Right atrial flutter includes upper loop reentry, free wall reentry and figure of eight reentry. Left atrial flutter includes mitral annular atrial flutter, pulmonary vein-related atrial flutter and left septal atrial flutter. Radiofrequency ablation of the isthmus between the boundaries can eliminate these arrhythmias

    Three-Neutrino MSW Effect and the LNW Mass Matrix

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    We review recent work on analytical solutions to the MSW equations for three neutrino flavours, for exponential and linear potentials. An application to a particular mass matrix is also discussed. The three neutrino masses are determined, respectively, to be 0.001--0.004, and roughly 0.01 and 0.05 eV.Comment: 7 pages, presented at Scandinavian Neutrino Workshop, Uppsala, February 8-10, 2001, to appear in the proceedings, Physica Scripta. Conference info at http://www3.tsl.uu.se/~damet/neutrino/first.htm

    Heat kernel analysis on semi-infinite Lie groups

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    This paper studies Brownian motion and heat kernel measure on a class of infinite dimensional Lie groups. We prove a Cameron-Martin type quasi-invariance theorem for the heat kernel measure and give estimates on the LpL^p norms of the Radon-Nikodym derivatives. We also prove that a logarithmic Sobolev inequality holds in this setting.Comment: 35 page

    Squark/gluino searches in hadronic channels with CMS

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    These proceedings summarize the results of four analyses which searched for squarks and gluinos in hadronic final states with missing transverse momentum in 2.3 fb−1^{-1} of data in proton-proton collisions at s=13\sqrt{s}=13 TeV collected in the year 2015 with the CMS detector at the CERN LHC. Each analysis is characterized by a different kinematic variable that is sensitive to the presence of invisible particles, e.g., MT2M_\text{T2}, αT\alpha_{\text{T}}, and razor variables. We observed no significant deviation from the standard model prediction and placed limits on the production cross sections and the masses of squarks and gluinos in simplified models of supersymmetric models. The limits are significantly extended from the previous results.Comment: Proceedings for 4th Conference on Large Hadron Collider Physics 2016 (LHCP 2016), Lund, Swede

    Hypoelliptic heat kernel inequalities on Lie groups

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    This paper discusses the existence of gradient estimates for second order hypoelliptic heat kernels on manifolds. It is now standard that such inequalities, in the elliptic case, are equivalent to a lower bound on the Ricci tensor of the Riemannian metric. For hypoelliptic operators, the associated "Ricci curvature" takes on the value -\infty at points of degeneracy of the semi-Riemannian metric associated to the operator. For this reason, the standard proofs for the elliptic theory fail in the hypoelliptic setting. This paper presents recent results for hypoelliptic operators. Malliavin calculus methods transfer the problem to one of determining certain infinite dimensional estimates. Here, the underlying manifold is a Lie group, and the hypoelliptic operators are invariant under left translation. In particular, "L^p-type" gradient estimates hold for p\in(1,\infty), and the p=2 gradient estimate implies a Poincar\'e estimate in this context.Comment: 22 pages, 0 figures; final journal versio

    Missing E_T Reconstruction with the CMS Detector

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    The CMS experiment uses missing E_T to both measure processes in the Standard Model and test models of physics beyond the Standard Model. These proceedings show the performance of the missing E_T reconstruction evaluated by using 4.6 fb-1 of proton-proton collision data at the center-of-mass energy 7 TeV collected in 2011 with the CMS detector at the Large Hadron Collider. Missing E_T was reconstructed based on a particle-flow technique. Jet energy corrections were propagated to missing E_T. After anomalous signals and events were addressed, the missing E_T spectrum was well reproduced by MC simulation. The multiple proton-proton interactions in a single bunch crossing, pile-up events, degraded the performance of the missing E_T reconstruction. Mitigations of this degradation have been developed.Comment: 6 pages, Proceedings for CALOR 2012, 15th International Conference on Calorimetry in High Energy Physic