Effective interaction and unified description of nuclear processes

A mean field calculation for obtaining the equation of state (EOS) for nuclear matter from a density dependent M3Y interaction (DDM3Y) supplemented by a zero-range potential is performed. The energy per nucleon is minimized to obtain ground state of the symmetric nuclear matter (SNM). The constants of density dependence of the effective interaction are obtained by reproducing the saturation energy per nucleon and the saturation density of SNM. The EOS of SNM, thus obtained, provide reasonably good estimate of nuclear incompressibility. The microscopic proton-nucleus and α-nucleus interaction potentials are obtained by single folding the density of the daughter nucleus and double folding the densities of the α and the daughter nuclei, respectively, with DDM3Y effective interaction whose density dependence is determined from nuclear matter calculations. The quantum mechanical tunneling probability is calculated within the WKB approximation using these nuclear potentials. These calculations provide reasonable estimates for the observed proton radioactivity lifetimes and α decay lifetimes including those of new superheavy elements 112, 114, 116 and the element 294118 and of some decay products and of the consecutive α decay chains of the two isotopes 287115 and 288115. These potentials also provide good descriptions for elastic and inelastic scattering of protons from nuclei 18Ne, 18O etc. and the deformation parameters extracted from inelastic scattering are in agreement with those extracted from the reduced electric quadrupole transition rates. The EOS for asymmetric nuclear matter is calculated by adding to the isoscalar part, the isovector component of M3Y interaction. The SNM and pure neutron matter EOS are then used to calculate the nuclear symmetry energy which is consistent with that extracted from the isospin diffusion in heavy-ion collisions at intermediate energies. The calculated β equilibrium proton fraction forbids direct URCA process which is consistent with the fact that there are no strong indications that fast cooling occurs. (author)