The emergence of the Cabibbo angle in non-degenerate coupled systems of fermions

Investigating, in direct continuation of our previous paper hep-ph/0606303 the implications of the non-unitarity of mixing matrices for non-degenerate coupled systems that we demonstrated there, we examine more accurately the vicinity of Cabibbo-like mixing in quantum field theory. We show that it is possible to preserve one of its main features, namely that, in the space of mass eigenstates, the two requirements -- of universality for weak diagonal currents and -- of the absence of their non-diagonal counterparts, although not fulfilled separately any more, can however reduce to a single condition for a unique mixing angle theta\_c. This leads to tan (2 theta\_c)=+/- 1/2, or cos theta\_c \approx 0.9732, only 7/10000 away from experimental results. No mass ratio appears in the argumentation.Comment: This is a different version of hep-ph/0607193, with a simplified argumentation, a clearer connection with hep-ph/0606303. The solution for the Cabibbo angle is also expressed in terms of the golden number. To appear in Phys. Lett.

Quark Lagrangian diagonalization versus non-diagonal kinetic terms

Loop corrections induce a dependence on the momentum squared of the coefficients of the Standard Model Lagrangian, making highly non-trivial (or even impossible) the diagonalization of its quadratic part. Fortunately, the introduction of appropriate counterterms solves this puzzle.Comment: 2 pages, 1 figur

Ocean Governance and Maritime Security in a Placeful Environment: The Case of the European Union

Adopting a critical geopolitics approach that accounts for the mutually reinforcing link between geo-informed narratives and power projection practices, this article proposes that ocean governance and maritime security have translated into states’ and regional organisations’ increasing control over maritime spaces. This leads to a certain territorialisation of the sea, not so much from a sovereignty and jurisdictional perspective but from a functional and normative perspective. The article starts by discussing the ways oceans have been represented and shows that they are far from a placeless void, both in practice and in discourse. The article then frames the analysis of ocean governance and maritime security within critical geopolitics, and elaborates on the case of the European Union’s narrative and practice. It concludes on the mutually reinforcing link between discourse and practice in the field of ocean governance and maritime security in general, and on the consequences in terms of power projection for the EU in particular. Scholars working on ocean governance and maritime security are encouraged to challenge the traditional view that oceans are placeless

Wide range and tunable linear TMR sensor using two exchange pinned electrodes

A magnetic tunnel junction sensor is proposed, with both the detection and the reference layers pinned by IrMn. Using the differences in the blocking temperatures of the IrMn films with different thicknesses, crossed anisotropies can be induced between the detection and the reference electrodes. The pinning of the sensing electrode ensures a linear and reversible output. It also allows tuning both the sensitivity and the linear range of the sensor. The authors show that the sensitivity varies linearly with the ferromagnetic thickness of the detection electrode. It is demonstrated that an increased thickness leads to a rise of sensitivity and a reduction of the operating range

Discrete symmetries and the propagator approach to coupled fermions in Quantum Field Theory. Generalities. The case of a single fermion-antifermion pair

Starting from Wigner's symmetry representation theorem, we give a general account of discrete symmetries (parity P, charge conjugation C, time-reversal T), focusing on fermions in Quantum Field Theory. We provide the rules of transformation of Weyl spinors, both at the classical level (grassmanian wave functions) and quantum level (operators). Making use of Wightman's definition of invariance, we outline ambiguities linked to the notion of classical fermionic Lagrangian. We then present the general constraints cast by these transformations and their products on the propagator of the simplest among coupled fermionic system, the one made with one fermion and its antifermion. Last, we put in correspondence the propagation of C eigenstates (Majorana fermions) and the criteria cast on their propagator by C and CP invariance.Comment: 37 pages, LaTeX. version to appear in "Annals of Physics (N.Y.)

New DRIE-Patterned Electrets for Vibration Energy Harvesting

This paper is about a new manufacturing process aimed at developing stable SiO2/Si3N4 patterned electrets using a Deep Reactive Ion Etching (DRIE) step for an application in electret-based Vibration Energy Harvesters (e-VEH). This process consists in forming continuous layers of SiO2/Si3N4 electrets in order to limit surface conduction phenomena and is a new way to see the problem of electret patterning. Experimental results prove that patterned electrets charged by a positive corona discharge show excellent stability with high surface charge densities that may reach 5mC/m^2 on 1.1\mu m-thick layers, even with fine patterning and harsh temperature conditions (up to 250{\deg}C). This paves the way to new e-VEH designs and manufacturing processes.Comment: Proc. European Energy Conference, 201

Coupling techniques for nonlinear hyperbolic equations. III. The well-balanced approximation of thick interfaces

We continue our analysis of the coupling between nonlinear hyperbolic problems across possibly resonant interfaces. In the first two parts of this series, we introduced a new framework for coupling problems which is based on the so-called thin interface model and uses an augmented formulation and an additional unknown for the interface location; this framework has the advantage of avoiding any explicit modeling of the interface structure. In the present paper, we pursue our investigation of the augmented formulation and we introduce a new coupling framework which is now based on the so-called thick interface model. For scalar nonlinear hyperbolic equations in one space variable, we observe that the Cauchy problem is well-posed. Then, our main achievement in the present paper is the design of a new well-balanced finite volume scheme which is adapted to the thick interface model, together with a proof of its convergence toward the unique entropy solution (for a broad class of nonlinear hyperbolic equations). Due to the presence of a possibly resonant interface, the standard technique based on a total variation estimate does not apply, and DiPerna's uniqueness theorem must be used. Following a method proposed by Coquel and LeFloch, our proof relies on discrete entropy inequalities for the coupling problem and an estimate of the discrete entropy dissipation in the proposed scheme.Comment: 21 page

Liquid transport in scale space

International audienceWhen a liquid stream is injected into a gaseous atmosphere, it destabilizes and continuously passes through different states characterized by different morphologies. Throughout this process, the flow dynamics may be different depending on the region of the flow and the scales of the involved liquid structures. Exploring this multi-scale, multi-dimensional phenomenon requires some new theoretical tools, some of which need yet to be elaborated. Here, a new analytical framework is proposed on the basis of two-point statistical equations of the liquid volume fraction. This tool, which originates from single phase turbulence, allows us notably to decompose the fluxes of liquid in flow–position space and scale space. Direct numerical simulations of liquid–gas turbulence decaying in a triply periodic domain are then used to characterize the time and scale evolution of the liquid volume fraction. It is emphasized that two-point statistics of the liquid volume fraction depend explicitly on the geometrical properties of the liquid–gas interface and in particular its surface density. The stretch rate of the liquid–gas interface is further shown to be the equivalent for the liquid volume fraction (a non-diffusive scalar) of the scalar dissipation rate. Finally, a decomposition of the transport of liquid in scale space highlights that non-local interactions between non-adjacent scales play a significant role

Sex differences in brain plasticity: a new hypothesis for sex ratio bias in autism.

Several observations support the hypothesis that differences in synaptic and regional cerebral plasticity between the sexes account for the high ratio of males to females in autism. First, males are more susceptible than females to perturbations in genes involved in synaptic plasticity. Second, sex-related differences in non-autistic brain structure and function are observed in highly variable regions, namely, the heteromodal associative cortices, and overlap with structural particularities and enhanced activity of perceptual associative regions in autistic individuals. Finally, functional cortical reallocations following brain lesions in non-autistic adults (for example, traumatic brain injury, multiple sclerosis) are sex-dependent. Interactions between genetic sex and hormones may therefore result in higher synaptic and consecutively regional plasticity in perceptual brain areas in males than in females. The onset of autism may largely involve mutations altering synaptic plasticity that create a plastic reaction affecting the most variable and sexually dimorphic brain regions. The sex ratio bias in autism may arise because males have a lower threshold than females for the development of this plastic reaction following a genetic or environmental event

Mixed-convection from a bundle of heating cylinders in a cross-flow air-circulation. Experiment and analysis

Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.Within the framework of radioactive waste management, the VALIDA program started to provide reliable data for the validation of numerical tools used to model the cooling of spent nuclear fuel containers in dry storage facilities. The design of such facilities implies thermal-hydraulic calculations in order to predict containers and wall temperatures. One has to make sure that these temperatures never exceed critical values. The understanding of mixed-convection flow in realistic conditions and more particularly the interaction between a global cross-flow circulation and local natural convection effects is a key point of these design studies. VALIDA experiments were carried out in this way at CEA on a multi canister configuration (7 rows heated tube bundle mounted vertically) in a special wind tunnel (length:12m, height: 3m width: 2m13) and cooled by a cross-flow air circulation. During the experiments, the air flow rate, the velocity profile and the heating power are controlled and have been adjusted to simulate various thermal-hydraulic conditions. A staggered tubes of seven rows of heated tubes (diameter 0.64m and height 2m) are placed in the wind tunnel, the 18 canisters arrangement use a triangular pitch (P/D = 1.66). Instrumentation includes thermocouples in the air flow, on the cylinders, and on the walls; the wind tunnel is rigged with two air-velocity measurement systems: LDV (Laser Doppler Velocimetry) and PIV (Particle Image Velocimetry). One presents the main experimental results reached with different values of the parameters: air velocity (0.25 to 1 m/s) and power density (300 to 600W/m²). From the downstream air measurements, a visualization of the temperature plume is obtained at different location behind the last tube. Measurements of air velocity are also performed with LDV laser in the air gap above the canisters. All the results show that the flow pattern of air strongly depends on the ratio of the buoyancy to the inertia forces. Convective transfers areas involving predominately forced or natural convection are distinguished thanks to established heat transfer correlations. A dimensionless buoyancy number Bo* is defined to characterize the experimental flow regimes obtained.cs201