Remarks—Outlook

The extension of the periodic system into the sectors hypermatter (strangeness) and antimatter is of general and astrophysical importance. Indeed, microseconds after the big bang the new dimensions of the periodic system, we have touched upon, certainly have been populated in the course of the baryo- and nucleo-genesis. Of course, for the creation of the universe, even higher dimensional extensions (charm, bottom, top) come into play, which we did not pursue here. It is an open question, how the depopulation (the decay) of these sectors influences the distribution of elements of our world today. Our conception of the world will certainly gain a lot through the clarification of these questions. 

The experimental verification of the decay of the vacuum is most important. A fundamental process like this must be experimentally clarified and soundly based. I hope that the proposed triggers for long time delay in the formation of 

It is clear however that these structural changes can occur only if the life time of the antibaryons in the nuclear interior is long enough. 

One should bear in mind that originally the RMF model was formulated within the Hartree and no-sea approximations. Implementing the Dirac sea may require serious revision of the model and inclusion of additional terms. Hartree calculations including the Dirac sea and Hartree-Fock calculations including exchange terms lead to smaller nucleon potentials in normal nuclei. Shallower potentials will produce smaller attraction for antinucleons, but the qualitative effect that the presence of antiprotons reduces repulsion and enhances attraction for nucleons will remain valid. We expect that the additional binding and compression of the nucleus will appear even for an antinucleon potential as low as 200 MeV. 

For the Gesellschaft fiir Schwerionenforschung (GSI), which I helped initiating in the sixties, the questions raised here could point to the way ahead. The FAIR project, meanwhile approved by the funding agencies, can—at least to some extent—follow this path. 

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