[en] Recent results on the masses of the π^-, K^-, anti p, and Σ^-, as well as on the magnetic moments of the anti p and Σ^-, are presented. The strong hadron-nucleus interaction is discussed for π^-, K^-, and anti p. Especially, the influence of precision measurements of light pionic atoms on the understanding of the π^--nucleus s-wave interaction is pointed out. New measurements on deformed nuclei with pions are discussed in terms of the quadrupole deformation of the neutron distribution. The difficulties in understanding the K^--nucleus interaction are demonstrated. Recent measurements on light anti p atoms are reported. In particular the first observed isotope effect in anti p atoms (¹⁶O/¹⁸O) is discussed in terms of differences in the anti pn and anti pp interaction

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[en] A novel method to study symmetry violation in the decay of neutral kaons is presented. The method makes use of initially pure K/sup 0/ and K-bar/sup 0/ beams, produced in pp-bar annihilations at LEAR. The detector and the tagging are described, and the envisaged physics is discussed

[en] The author reviews the study of the QED vacuum polarization using X-ray transitions in muonic atoms. (HSI)

[en] Symmetries play an impotant role in physics. In classical physics, space-time symmetry is built-in and the laws of elementary interactions are automatically invariant under parity inversion (P), or reflection of the system in a mirror, and time reversal (T); charge conjugation symmetry (C) is trivially preserved since no classical interaction mixes matter and antimatter. In the real world, currently described by quantum field therories having the property of local gauge invariance, both parity and charge conjugation symmetries are maximally violated by the weak interaction, although conserved in strong and electromagnetic interactions. In contrast, their product (CP) has so far been observed to have good symmetry in all systems except for the (weak) decay of the neutral kaon, where the CP-violating amplitude is very small (∼2x10^-3) compared with the CP-conserving amplitude. CP violation can be described within the standard model by some complex elements in the quark-mass mixing matrix, but its origin is far from understood. The authors discuss the potential of existing and planned facilities that allow the measurement of CP, T, and CPT violations in meson decays. Given the present excellent agreement of all (other) experimental measurements with predictions of the standard model, despite the acknowledged fault lines in the latter, it is of utmost importance to confront it with measurements of CP violation in different systems

[en] The widths and shifts of the atomic levels due to the strong pion-nucleus interaction are calculated. A formula with two phenomenological parameters is presented. These are determined from pionic data on ²⁸Si, ³²S and ⁴⁰Ca. The data on the 2p levels are used to predict the r.m.s. radii of the neutron distributions in some nuclei. (Auth.)

[en] Kaonic shifts and widths for ¹²C and ³²S are analysed using an optical potential, which selectively incorporates nuclear shell structure aspects as well as effects of Λ(1405) dynamics inside the nucleus. Good agreement with data is found and suggests a moderately repulsive interaction of the Λ(1405) with surrounding nucleons. (Auth.)

[en] The neural network first level trigger for the DIRAC experiment at CERN is presented. Both the neural network algorithm used and its actual hardware implementation are described. The system uses the fast plastic scintillator information of the DIRAC spectrometer. In 210 ns it selects events with two particles having low relative momentum; such events are selected with an efficiency of more than 0.94. The corresponding rate reduction for background events is a factor of 2.5

No abstract available

No abstract available