EXA2011

The Kbar-N system at rest makes a sensitive testing ground for the understanding of strong interaction at low energies. At the DAFNE electron-positron collider of Laboratori Nazionali di Frascati we study X-ray transitions of kaonic atoms, taking advantage of the low-energy kaons produced by Phi-mesons decaying nearly at rest. In the SIDDHARTA (Silicon Drift Detector for Hadronic Atom...

A brief summary of state-of-the-art analyses of kaonic atom data will be presented, showing good consistency between the various experiments of 30-40 years ago. Correlations between depths of real antikaon-nucleus potentials and the corresponding radii provide a link between phenomenology and 'microscopic' antikaon-nucleon interaction in the nuclear medium. Further studies...

Properties and structure of the Lambda (1405) are interesting both in themselves and in the context of few-body and many-body nuclear states of anti-K mesons. One of the old problems is the place of Lambda (1405) in the quark models and related symmetries. Another problem affecting the few body physics is related to the elastic anti-K nucleon scattering amplitude. The two approaches now...

An energy shift of the 2p level of kaonic 3He and 4He atoms is recently studied in theory and experiment. A theory predicting deeply bound kaonic nuclear states estimates a significant energy shift in kaonic 3He or 4He. The SIDDHARTA experiment measured the kaonic 3He and 4He 3d-2p X-ray transitions at the DAFNE e+e- collider. The strong interaction shifts of the kaonic 3He and 4He 2p...

Formation of $K^{-}pp$ in high-energy $p+p$ collision is an elementary doorway step to excite kaonic nuclear clusters in nuclei. The $K^{-}pp$ system has a structure of ${\mathrm{\Lambda }}^{\ast }$-$p$, where ${\mathrm{\Lambda }}^{\ast }$ is $\mathrm{\Lambda }(1405)$ embedded in the system. We have investigated theoretically how coupled-channel properties of $\mathrm{\Lambda }(1405)$ change inside the quasi-bound system, $K^{-}pp$, by using "generalized...

The energy level displacement of the excited np state of kaonic deuterium is calculated in terms of the P-wave scattering length of K^-d scattering. We solve the Faddeev equations for the amplitude of K^-d scattering in the fixed centre approximation and derive the complex P-wave scattering length of K^-d scattering in terms of the S-wave and P-wave scattering lengths of anti-KN ...