Abstract:

Within the last two decades there were the following novel developments in theory and phenomenology at ACCULINNA/ACCULINNA-2 group:

1. Development of consistent quantum-mechanical theory of two-proton radioactivity with precise treatment of the long-range correlations in the three-body Coulomb continuum.
2. Clarification of the role of «true» two-proton and two-neutron decays and «soft» dipole excitations in the process of «rapid» nucleosynthesys at the proton driplines (r- and rp-processes).
3. Development of data analysis methods for (few-body) decays of aligned states populated in direct reactions at intermediate energies (ACCULINNA/ACCULINNA-2 fragment separators at FLNR).
4. Development of data analysis methods for experiments with fragment tracking (the technique developed at GSI, Germany).
5. Prediction of possibility of very long-living states decaying via simultaneous emission of two or four neutrons. In certain limit this corresponds to possibility of novel types of radioactive decays: two-neutron and four-neutron radioactivities.
6. Studies of «transition dynamics» between different mechanisms of three-body decay. Proposed new method of width determination for two-body decays by studies of three-body correlations in the transition region.

The relevance of these developments to the past and prospective experimental scientific program of the ACCULINNA/ACCULINNA-2 group is discussed.