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Properties of positronium (Ps), its negative ion, and the recently discovered positronium molecule are briefly reviewed. Emphasis is on the recent progress and on quantities of current experimental interest, including the Ps atomic and molecular spectrum, and the ion lifetime.

Highlights of RIKEN radioactive beam experiments are reviewed. In particular the phenomena of giant soft dipole excitation of halo nuclei are closely discussed.

Coulomb excitations using radioactive beams are discussed. Applications of such reactions are described including soft dipole excitation of neutron halo nuclei, collective E2 excitation of 32 Mg and astrophysically interesting 8 B breakup.

A general method for the calculation of second order effects in the Coulomb dissociation is presented in the small ξ-limit avoiding the introduction of intermediate states. The amplitudes for a dipole excitation are analytically calculated in a simple model for the projectile with a zero-range force. The model is applied to the excitation of 11 Li at projectile energies of 28 and 800 MeV nucleon . The angular and energy distribution of the fragments and post-acceleration effects are examined in first and second order perturbation theory as well as the sudden approximation.

Cross sections for the electromagnetic dissociation of 197 Au targets by 1.7 A GeV 20 Ne and 1 A GeV 88 Kr, 197 Au and 209 Bi beams have been measured by an activation method. Weizsacker-Williams calculations show that the experimental 1n cross sections can be understood by first order excitation of the giant dipole and the isoscalar giant quadrupole resonance. In contrast, the 3n cross sections show a much stronger Z proj - dependence, which can only be explained by a dominant contribution from two-phonon giant dipole excitation.

The parent analog of the giant dipole resonance in 28 Si is studied by means of the (n, p) reaction. The continuum contribution to the giant dipole region was estimated by a phenomenological parameterization. The observed cross section exhausts 31% of the SJ sum rule; 88% of the GT sum rule or 67% of the Myers-Swiatecki prediction. A comparison is made to the giant resonance region observed in the 28 Si(p, p') reaction which was recently used, via comparison to 28 Si(α, α'), to infer that the GDR in 28 Si is not excited or at least not seen in (p, p').