相关论文: Non-Perturbative Renormalisation and Kaon Physics

We consider here the Feynman amplitudes of renormalizable non-commutative quantum field theory models. Different representations (the parametric and the Mellin one) are presented. The latter further allows the proof of meromorphy of a…

A novel theoretical framework, the inverse problem approach, is proposed to calculate non-perturbative quantities in quantum chromodynamics (QCD). Based on the dispersion relation of quantum field theory, this approach determines unknown…

We study the in-medium modification of the isovector pi N amplitude using a non-linear representation of the sigma model but keeping the scalar degree of freedom. We check that our result does not depend on the representation. We discuss…

We discuss a number of old and new methods for computing $K\to\pi\pi$ amplitudes on the lattice. They all involve a non-perturbative determination of matching coefficients. We show how problems related to operator mixing can be greatly…

We suggest a renewed view on non-renormalizable interactions treated perturbatively within a kinematically dependent renormalization procedure. It is based on the usual BPHZ R-operation which is equally applicable to any local QFT…

The non-leptonic hyperon decays are analyzed up to one-loop order including all counterterms in the framework of heavy baryon chiral perturbation theory. We use the exchange of the spin-3/2 decuplet resonances as an indication of which…

Rare Kaon decays and CP violation are important tools to test the Standard Model and its extensions. We describe kaon physics observables testing CP violation and more generally short distance physics. Channels under consideration will be K…

In bosonic end perturbative calculations for quantum mechanical anyon systems a regularization and renormalization procedure, analogous to those used in field theory, is necessary. I examine the reliability and the physical interpretation…

The problem of $\gamma \pi \to \pi \pi$ is studied using the axial anomaly, elastic unitarity, analyticity and crossing symmetry. The solution of the integral equation for this amplitude is given by an iteration procedure.The final solution…

We compare the low-energy partial wave analyses $\pi N$ scattering with a high-energy data via finite energy sum rules. We construct a new set of amplitudes by matching the imaginary part from the low-energy analysis with the high-energy,…

We study the kaon polarizabilities in the framework of Chiral Perturbation Theory to order $p^4$. For the neutral kaon we find that them vanish and they have the first non-zero contribution to order $p^6$. We also emphasize the theoretical…

We discuss the application of two-particle-irreducible (2PI) functional techniques to gauge theories, focusing on the issue of non-perturbative renormalization. In particular, we show how to renormalize the photon and fermion propagators of…

Perturbative renormalization group theory is developed as a unified tool for global asymptotic analysis. With numerous examples, we illustrate its application to ordinary differential equation problems involving multiple scales, boundary…

We quantify the important effect of strong final state interactions in the weak $K\to 2\pi$ amplitudes, using the measured $\pi$-$\pi$ phase shifts with J=0 and $I=0,2$. The main results of this analysis, with their implications for…

We propose an improved method of the equation of motion approach to study the Kondo problem in spin-dependent non-equilibrium conditions. We find that the previously introduced additional renormalization for non-equilibrium Kondo effects is…

We investigate a one dimensional quantum mechanical model, which is invariant under translations and dilations but does not respect the conventional conformal invariance. We describe the possibility of modifying the conventional conformal…

The amplitude for the anomalous transitions gamma pi(+) -> pi(0) pi(+) is analyzed within Chiral Perturbation Theory including electromagnetic interactions. The presence of a t-channel one-photon exchange contribution induces sizeable e^2…

Interferometry with neutral kaons at KLOE is reviewed. The preliminary results on phi->KS KL->pi+pi- pi+pi- and decoherence parameter are presented. The impact of C-even background and regenerators is shortly discussed and updated. Finally…

We show that lattice calculation of K --> pi pi and $epe$ amplitudes for (8,1) and (27,1) operators to O(p^4) in chiral perturbation theory is feasible when one uses K --> pi pi computations at the two unphysical kinematics allowed by the…

We compute the renormalization factors of four-quark operators needed for the study of $K\to\pi\pi$ decay in the $\Delta I=3/2$ channel. We evaluate the Z-factors at a low energy scale ($\mu_0=1.145 \GeV$) using four different…