[en] Radiative meson decays are a fertile field for chiral perturbation theory. Chiral symmetry together with gauge invariance yield stringent constraints on radiative decay amplitudes. In addition to predicting decay rates and spectra, the chiral approach allows for a unified description of CP violation in radiative K decays. The chiral viewpoint in the recent controversy over the magnitude of two-photon exchange in the decay K_L→ π⁰e⁺e^- is exposed. The radiative decay η→π⁰γγ is discussed as an intriguing case where the leading result of chiral perturbation theory seems to be too small by two orders of magnitude in rate. 32 refs., 3 figs. (Author)

[en] The ambiguities in the off-shell behaviour of spin-1 exchange can be resolved to O(p⁴) in the chiral low-energy expansion if the asymptotic behaviour of QCD is properly incorporated. As a consequence, the chiral version of vector (and axial-vector) meson dominance is model independent. Additional high-energy constraints motivated by QCD determine the V,A resonance couplings uniquely. In particular, QCD in its effective chiral realization sucessfully predicts Γ(ρ→2π). 10 refs. (Author)

[en] The investigation of rare K decays calls for a unified treatment of short- and long-distance aspects as provided by chiral perturbation theory. For the standard model with three generations, the theoretical predictions for signals of CP violation in those decays are reviewed. With direct CP violation as the main target, special emphasis is given to the charge asymmetries in charged K decays and to the especially rare decays K_L → π⁰ll-bar. Time dependent rate asymmetries in K⁰ decays and the longitudinal muon polarization in K_L → μ⁺μ^- are also discussed. 50 refs., 3 figs., 1 tab. (Author)

[en] Possibilities and limits of future energy supply are outlined, then a brief into fusion technology is given. This technology is expected to make an important contribution to the supply of energy, before it can be utilized in large technology however a lot of questions remain to be answered. (UA)

[en] Prospects for testing QCD in non-leptonic weak decays are analyzed in the framework of the effective chiral Lagrangian of the Standard Model. 23 refs., 5 figs. (Author)

[en] The leading divergences of the generating functional for Green functions of quark currents between one-nucleon states are calculated with heat kernel techniques. The results allow for a chiral invariant renormalization of all two-nucleon Green functions of the pion-nucleon system to O(p³) in the low-energy expansion. (author)

[en] After a brief survey of effective field theories, the linear σ model is discussed as a prototype of an effective field theory of the standard model below the chiral symmetry breaking scale. Although it can serve as a toy model for the pion-nucleon interaction, the linear σ model is not a realistic alternative to chiral perturbation theory. The heavy baryon approach to chiral perturbation theory allows for a systematic low-energy expansion of Green functions and amplitudes with baryons. The chiral invariant renormalization of the effective field theory for the pion-nucleon system to O(p³) in the chiral expansion is reviewed. (authors)

[en] These lectures are meant to serve a twofold purpose. First, they contain an introduction to electroweak gauge theories for those who are not (or not yet) specialized in particle theory. The author tries to emphasize the physical requirements which almost inevitably lead to the concept of gauge theories. The second aim is to provide a background for the more advanced courses, in particular on grand unified theories and on dynamical symmetry breaking. Therefore, the emphasis is mostly on the properties of a general gauge theory and the standard model is then discussed as the simplest example to illustrate those properties. The author is concerned only with the perturbative aspects of gauge theories. (Auth.)

[en] The evidence for a possible geometrical understanding of the effective chiral Lagrangian for the ΔS = 1 non-leptonic weak interactions of pseudoscalar mesons is discussed. Both phenomenological arguments and the structure of the one-loop functional suggest a weak deformation of the geometrical objects vielbein and connection on the chiral coset space. (Author) 12 refs., 1 tab

[en] After a short introduction to chiral perturbation theory an attempt to relate the strong and the non-leptonic weak low-energy constants is reviewed. The weak deformation model is stimulated both by the geometrical structure of chiral perturbation theory and by phenomenological considerations. Applications to the radiative decays K → πγγ and K_L → γe⁺e^- are discussed. (Author) 38 refs., 4 figs