Formation of a new state of nuclear matter in nuclear fission

The mass distributions of asymmetric and symmetric fission of actinide nuclei can be explained. Fissile nuclei are internally clusterized into a $^{208}$Pb-like core and a cluster made of its valence nucleons. If the energy released by the dissociation is great enough, the superficial nucleons of the core can be transferred to the cluster in a kind of internal collision, occurring within 1.8 10$^{-25}$s,as can be demonstrated. This collision creates extreme conditions, and a new nucleon phase replaces the normal proton- and neutron-phases, but conserves their organization law. The transferred nucleons are statistically distributed between the valence shells of an A$_{H}$= 126 nucleon core and those of an A$_{L}$ = 82 nucleon core (or of an A$_{L}$ = 126 nucleon core in symmetric fission), with a distribution coefficient of 0.206. The closure of the A$_{L}$ = 126 nucleon shell separates the regions of asymmetric and symmetric fission. The great yield of the symmetric mode results from the appearance of fragment-pair Q$_{tot}$-values greater than their own Coulomb barrier, i.e. from barrier-free fission.