New way for the production of heavy neutron-rich nuclei

A new way is found to discover and examine unknown neutron-rich heavy nuclei at the ‘north-east’ part of the nuclear map. This ‘blank spot’ of the nuclear map can be reached neither in fusion–fission reactions nor in fragmentation processes widely used nowadays for the production of new nuclei. The present limits of the upper part of the nuclear map are very close to stability while the unexplored area of heavy neutron-rich nuclides along the neutron closed shell N = 126 (to the east of the stability line) is extremely important for nuclear astrophysics investigations and, in particular, for the understanding of the r-process of astrophysical nucleogenesis. A novel idea is proposed for the production of these nuclei via low-energy multi-nucleon transfer reactions. The estimated yields of neutron-rich nuclei are found to be rather high in such reactions and several tens of new nuclides can be produced, for example, in the near-barrier collision of 136Xe with 208Pb. This finding may spur new studies at heavy-ion facilities and should have significant impact on future experiments. Communicated by Professor J Aichelin