Detailed theoretical study of the decay properties of states in the ${}^7\mathrm{He}$ nucleus within an ab initio approach

The energies and decay widths of the states of the exotic ${}^7\mathrm{He}$ nucleus are studied in an ab initio approach. The spectrum of these states is calculated using the no-core shell model (NCSM) and a corresponding extrapolation procedure. The Daejeon16 potential, well proved on a large amount of data, is used in the calculations. The previously developed NCSM-based approach, which includes a method for constructing the basis of functions of cluster channels and a procedure for matching the cluster form factors obtained within this method with the corresponding asymptotic wave functions, is applied to compute the decay widths of the levels. The possibilities of the approach are demonstrated for calculating the partial decay widths of nuclear states into various channels that strongly differ in type of fragmentation, spin, angular momentum of relative motion, and amplitude. The results obtained are compared with the results of other microscopic calculations.

Figure 1

Illustration of the conditions for matching CFFs in the “new” and “old” definitions with an asymptotic function.