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The radiative corrections to double-Dalitz (P → l ¯ l l ¯ ' l ') $({P\rightarrow\overline ll\overline l'l'})$ decays are revisited and completed up to next-to-leading order in QED, finding mild differences with respect to previous studies. These might be relevant for extracting information about the mesons transition form factors, which play an important role in determining the hadronic light-by-light contribution to the anomalous magnetic moment of the muon. [ABSTRACT FROM AUTHOR]

This paper deals with flow around a bluff body of hyperboloid shape. It consists of results gathered in the course of research by means of Particle Image Velocimetry (PIV). The experiments were carried out by means of low-frequency 2D PIV in a range of Reynolds numbers from 40000 to 50000. A hyperboloid-shaped model was measured in a wind tunnel with a modelled atmospheric boundary layer (and additionally, in a low-speed wind tunnel with low turbulence). The model was tested in a subcritical range of Reynolds numbers and various planes in a wake of the model were captured with the intention of getting an estimation of 3D flow structures. The tunnel with the modelled atmospheric boundary layer has a high rate of turbulence, so the influence of the turbulence of incoming flow on the wake could be outlined. The ratio of the height of the model to a thickness of the modelled boundary layer in the tunnel was 1/3, meaning the turbulence in the boundary layer strongly influenced the flow around the model; it suppresses the wake which leads to a lot shorter area of recirculation than low turbulence incoming flow would cause. [ABSTRACT FROM AUTHOR]

A review of familiar results of the three-point Green functions of currents in the odd-intrinsic parity sector of QCD is presented. Such Green functions include very well-known examples of VVP, VAS or AAP correlators. We also present new results for VVA and AAA Green functions that have not yet been studied extensively in the literature before, more importantly with a phenomenological study and a discussion of the high-energy behaviour and its relation to the QCD condensates. [ABSTRACT FROM AUTHOR]

We briefly summarize experimental and theoretical results on the rare decay π0 → e+e-. Two-loop QED corrections are reviewed and the bremsstrahlung contribution beyond the soft-photon approximation is analytically calculated. Using the leading logarithm approximation, the possible contribution of QCD corrections is estimated. The complete result can be used to fit the value of the contact interaction coupling Xr to the recent KTeV experiment with the result X(r)(Mρ) = 4.5 ± 1.0. [ABSTRACT FROM AUTHOR]

A review of familiar results of the three-point Green functions of currents in the odd-intrinsic parity sector of QCD is presented. Such Green functions include very well-known examples of VVP,VAS or AAP correlators. We also shortly present some of the new results for VVA and AAA Green functions with a discussion of their high-energy behaviour and its relation to the QCD condensates. [ABSTRACT FROM AUTHOR]

This paper is interested in the mathematical modeling and approximation of the turbulent flow with strong anisotropy for the case of flow in a rack station. Turbulent models based on Boussinesq eddy viscosity assumption are traditionally employed for the solution of these types of flows. Linear eddy viscosity model and the assumption of isotropic Reynolds stress tensor are typically used in many cases. This leads to certain limitations in the cases of either separated flow or flow with significant curvature of the mean flow. The application of full Reynolds stress model is suitable for this case but it introduces at least seven additional equations and the model has much higher demand for computing time, grid parameters and discretization schemes. Therefore the Explicit Algebraic Reynolds Stress Model (EARSM) is used here. This model is based on two equations k - omega turbulence model with the nonlinear eddy viscosity model and explicit terms for anisotropic parts of the Reynolds stress tensor. The computational requirements are similar to the standard k - omega model. The numerical and experimental results from PIV measurement are compared. [ABSTRACT FROM AUTHOR]