Skyrme forces and isotopic dependence of evaporation residue cross-section in the decay of 252,254−256No∗ formed in 204,206,207,208Pb+48Ca reactions.

The fusion evaporation residue (ER) cross-sections σ x n for the decay of compound nucleus (CN) 2 5 2 , 2 5 4 , 2 5 5 , 2 5 6 No ∗ via 1 n –4 n decay channels, synthesized in 2 0 4 , 2 0 6 , 2 0 7 , 2 0 8 Pb + 4 8 Ca reaction, are studied, including deformations β 2 i for cold-optimum orientations 𝜃 i at various 4 8 Ca excitation energies of E ∗ = 2 0 to 45 MeV. For the nuclear interaction potentials, we use the Skyrme energy density functional (SEDF)-based on semi-classical extended Thomas Fermi (ETF) approach under frozen density approximation on our earlier study of fusion ER cross-section for the decay of 2 5 2 , 2 5 4 − 2 5 6 No ∗ , via 1 n –4 n decay channels synthesized in 2 0 4 , 2 0 6 − 2 0 8 Pb + 4 8 Ca reaction based on the Dynamical cluster-decay model (DCM) using the pocket formula for nuclear proximity potential in which the above reaction was investigated by using hot-optimum orientations. In this work the above reaction has been investigated in two parts, in the first part, E ∗ < 2 5 MeV is used for cold elongated configurations and in the second part, E ∗ > 2 5 MeV is used for hot compact configurations. The Skyrme forces used here are the old SIII, and new GSkI and KDE0(v1) given for both normal and isospin-rich nuclei, with densities added in frozen density approximation. Interestingly, independent of the Skyrme force used, the DCM gives an excellent fit within one-parameter fitting of Δ R to the measured data on fusion ER for cold fusion. Of all the three Pb-isotopes and three E ∗ considered, at each E ∗ , the Δ R is largest for compound system with mass numbers 256 and 254, and smallest for 252, which means that the neutrons emission occur earliest for 256, then 255 followed by 254 and finally for 252, in complete agreement with experimental data. The possible fusion–fission (ff) and quasi-fission (qf) mass-regions of fragments on DCM are also predicted. The DCM with Skyrme forces is further used to look for all the possible target-projectile (t - p) combinations forming the "cold" CN 2 5 4 No ∗ at the CN excitation energy of E ∗ for "optimum cold" configurations. The fusion ER cross-sections, for the proposed new reactions in synthesizing the CN 2 5 4 No ∗ , are also estimated for the future experiments. [ABSTRACT FROM AUTHOR]