Isospin breaking in pion and Ke4K_{e4} form factors

Isospin breaking in the $K_{\ell 4}$ form factors induced by the difference between charged and neutral pion masses is discussed within a framework built on suitably subtracted dispersion representations. The $K_{\ell 4}$ form factors are constructed in an iterative way up to two loops in the low-energy expansion by implementing analyticity, crossing, and unitarity due to two-meson intermediate states. Analytical expressions for the phases of the two-loop form factors of the $K^\pm\to\pi^+\pi^- e^\pm \nu_e$ channel are presented, allowing one to connect the difference of form-factor phase shifts measured experimentally (out of the isospin limit) and the difference of $S$- and $P$-wave $\pi\pi$ phase shifts studied theoretically (in the isospin limit). The dependence with respect to the two $S$-wave scattering lengths $a_0^0$ and $a_0^2$ in the isospin limit is worked out in a general way, in contrast to previous analyses based on one-loop chiral perturbation theory. The results on the phases of the $K^\pm\to\pi^+\pi^- e^\pm \nu_e$ form factors obtained by the NA48/2 collaboration at the CERN SPS are reanalysed including isospin-breaking correction to extract values for the scattering lengths $a_0^0$ and $a_0^2$.Comment: 15 pages, 3 figures, prepared for the proceedings of the XIth Confinement and Hadron Spectrum Conference, Saint-Petersburg, Sept. 8-12, 201

Ease of Using a Dedicated Percutaneous Closure Device after Inadvertent Cannulation of the Subclavian Artery: Case Report

Inadvertent puncture of the subclavian artery is a relatively frequent and potentially disastrous complication of attempted central venous access. Due to its noncompressible location, accidental subclavian arterial cannulation may result in hemorrhage as the sheath is removed. We report a new case of successful percutaneous closure of the subclavian artery which had been inadvertently cannulated, using a closure device based on a collagen plug (Angio-Seal, St. Jude Medical). This was performed in a patient who had received maximal antiplatelet and anticoagulation therapies because of prior coronary stenting in the context of cardiogenic shock. There was no prior angiographic assessment, as arterial puncture was presumed to have been distal to the right common artery and vertebral arteries. No complications were observed in this high-risk patient, suggesting that this technique could be used once the procedure has been evaluated prospectively

Two-loop representations of low-energy pion form factors and pi-pi scattering phases in the presence of isospin breaking

Dispersive representations of the pi-pi scattering amplitudes and pion form factors, valid at two-loop accuracy in the low-energy expansion, are constructed in the presence of isospin-breaking effects induced by the difference between the charged and neutral pion masses. Analytical expressions for the corresponding phases of the scalar and vector pion form factors are computed. It is shown that each of these phases consists of the sum of a "universal" part and a form-factor dependent contribution. The first one is entirely determined in terms of the pi-pi scattering amplitudes alone, and reduces to the phase satisfying Watson's theorem in the isospin limit. The second one can be sizeable, although it vanishes in the same limit. The dependence of these isospin corrections with respect to the parameters of the subthreshold expansion of the pi-pi amplitude is studied, and an equivalent representation in terms of the S-wave scattering lengths is also briefly presented and discussed. In addition, partially analytical expressions for the two-loop form factors and pi-pi scattering amplitudes in the presence of isospin breaking are provided.Comment: 57 pages, 12 figure

Response to Letter to Editor: “Is There a Potential Benefit to Increased Irrigation Channels During Radiofrequency Ablation? Results From a Two-Center Prospective Randomized Study”

FLWINinfo:eu-repo/semantics/publishe

Contribution à la compréhension des mécanismes électrophysiologiques de la fibrillation auriculaire et application pour le traitement invasif percutané

Doctorat en Sciences médicalesinfo:eu-repo/semantics/nonPublishe

Another use for radiofrequency energy during an atrial fibrillation ablation procedure.

Case ReportsJournal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Left atrial vagal stimulation resulting in atrial fibrillation driven from the right atrium.

Case ReportsJournal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe