Neutron-halo nuclei in cold synthesis and cluster decay of heavy nuclei: Z=104 nucleus as an example.

Abstract

Nuclei at the neutron-drip line are studied. The light neutron-halo nuclei are found to play an important role for both cold fusion reactions and exotic cluster decay studies of heavy nuclei at the neutron-drip line. For cold fusion reactions, beams of neutron-halo nuclei are shown to occur as natural extensions of the conventional lighter beams but with the corresponding target nuclei as the heavy neutron-rich radioactive nuclei. Thus, in synthesizing the various isotopes of a neutron-rich cool compound nucleus, both the target and projectile nuclei have to be richer in neutrons, with their proton numbers remaining the same. On the other hand, neutron-halo (cluster) decays are favored for a relatively less neutron-rich parent nucleus. Possible consequences of this work for the shell structure effects in neutron-rich heavy nuclei are also pointed out. This follows from the fact that the so far observed phenomena of both cold fusion and cluster radioactivity are associated with closed or nearly closed shell nuclei. Calculations are made for {sup 274,288}104, using the quantum mechanical fragmentation theory for cold fusion reaction studies and a performed cluster model for cluster decay studies.