Single-particle shell strengths near the doubly magic nucleus Ni-56 and the Ni-56(p,gamma)Cu-57 reaction rate in explosive astrophysical burning

摘要

Angle-integrated cross-section measurements of the Ni-56(d,n) and (d,p) stripping reactions have been performed to determine the single-particle strengths of low-lying excited states in the mirror nuclei pair Cu-57-Ni-57 situated adjacent to the doubly magic nucleus Ni-56. The reactions were studied in inverse kinematics utilizing a beam of radioactive Ni-56 ions in conjunction with the GRETINA gamma-array. Spectroscopic factors are compared with new shell-model calculations using a full pf model space with the GPFX1A Hamiltonian for the isospin-conserving strong interaction plus Coulomb and charge-dependent Hamiltonians. These results were used to set new constraints on the Ni-56(p,gamma)Cu-57 reaction rate for explosive burning conditions in x-ray bursts, where Ni-56 represents a key waiting point in the astrophysical rp-process. (C) 2019 The Author(s). Published by Elsevier B.V.