Asymmetric fission ofU236in a self-consistentK-matrix model

The phenomenological single-particle Hamiltonian of Meldner is rederived as a renormalized single-particle $K$ matrix and is used to calculate the propreties of ${}_{}{}^{236}{}_{}{}^{}\mathrm{U}$ on the fission path from the ground state to scission into asymmetric fragments. Substantial radial density fluctuations or "bubble configurations" are observed as well as a displacement of the neutron center of mass relative to that of the protons. It is also found that the presence of a deep minimum and saddle near the touching point can be observed for one of the parameter sets of the interaction. The parameters of our deformation and atomic number independent model were obtained by fitting to the experimental properties of ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$, ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$, and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ and nuclear matter. The present results illustrate the importance of using a nonorthogonal two-oscillator basis as well as taking into account the properties of nuclear matter.