We review some recent theoretical results on rare kaon decays. Particular attention is devoted to find Standard Model tests. This is theoretically easy in K → πνν, while a careful study of the long distance contributions is needed for KL → πee, KL → μμ and K → ππγ .

The current status of the study of rare kaon decays is reviewed. Future prospects are discussed. a Submitted to the proceedings of the XXXVth Rencontres de Moriond session devoted to Electroweak Interactions and Unified Theories.

The NA48 Collaboration has obtained several new results on kaon and neutral hyperon decays. For hyperons we present new, very precise measurements on the Ξ lifetime and the decay asymmetries of Ξ → Λγ and Ξ → Σγ. On kaon decays, we report on the first observation of the interference term between Inner Bremsstrahlung and Direct Emission in K± → π±π0γ and on a new, accurate measurement of the for...

This presentation reviews recent developments in the understanding of lowenergy pionand kaon-nucleon interactions as they relate to deeply bound pionic atoms and possible antikaon-nuclear bound states. A brief update is given on 1s states of pionic atoms, summarizing their theoretical interpretation based on in-medium chiral effective field theory. This is followed by a stateof-the-art discussi...

In the recent year many new results from kaon decays have been reported from both the NA48 experiment at CERN and the KTeV experiment at Fermilab. Both experiments have new and improved measurements of the parameter Re( ′/ ) of direct CP violation in the neutral kaon system. Also several new results on rare and very rare KL decays were reported. In addition, the NA48 collaboration has performed...

The article reviews the physics related to kaon and antikaon production in heavy ion reactions at intermediate energies. Chiral dynamics predicts substantial modifications of the kaon properties in a dense nuclear environment. The status of the theoretical predictions as well as experimental evidences for medium effects such as repulsive/attractive mass shifts for K+/K− are reviewed. In the vic...

We identify the leading s-wave amplitudes of the SU(3) chiral meson-baryon Lagrangian with an effective coupled-channel potential which is iterated in a Lippmann-Schwinger equation. The strangeness S = −1 resonance Λ(1405) and the S11(1535) nucleon resonance emerge as quasi-bound states of anti-kaon/nucleon and kaon/Σ-hyperon. Our approach to meson photoproduction introduces no new parameters. ...

We identify the leading s-wave amplitudes of the SU(3) chiral meson-baryon Lagrangian with an effective coupled-channel potential which is iterated in a Lippmann-Schwinger equation. The strangeness S = −1 resonance Λ(1405) and the S 11 (1535) nucleon resonance emerge as quasi-bound states of anti-kaon/nucleon and kaon/Σ-hyperon. Our approach to meson photo-production introduces no new parameter...

I critically review recent lattice QCD results relevant for kaon phenomenology, as well as the methods that are used to obtain them. The focus is on calculations with N f = 2 and N f = 2 + 1 flavors of sea quarks. Concerning methodology, the subjects covered include a discussion of how best to extrapolate and/or interpolate results to the physical quark-mass point, a scheme for assessing the ex...