Microscopic coupled-channel calculation of proton and alpha inelastic scattering to the 41+ and 42+ states of 24Mg

The triaxial and hexadecapole deformations of the Kπ = 0+ and Kπ = 2+ bands of 24Mg have been investigated by the inelastic scatterings of various probes, including electrons, protons, and alpha(α) particles, for a prolonged time. However, it has been challenging to explain the unique properties of the scatterings observed for the 41+ state through reaction calculations. This paper investigates the structure and transition properties of the Kπ = 0+ and Kπ = 2+ bands of 24Mg employing the microscopic structure and reaction calculations via inelastic proton and α scattering. In particular, the E4 transitions to the 41+ and 42+ states are reexamined. The structure of 24Mg was calculated employing the variation after the parity and total angular momentum projections in the framework of the antisymmetrized molecular dynamics (AMD). The inelastic proton and α reactions were calculated by the microscopic coupled-channel (MCC) approach by folding the Melbourne g-matrix NN interaction with the AMD densities of 24Mg. Reasonable results were obtained on the properties of the structure, including the energy spectra and E2 and E4 transitions of the Kπ = 0+ and Kπ = 2+ bands owing to the enhanced collectivity of triaxial deformation. The MCC+AMD calculation successfully reproduced the angular distributions of the 41+ and 42+ cross sections of proton scattering at incident energies of Ep = 40–100MeV and α scattering at Eα = 100–400 MeV. This is the first microscopic calculation to describe the unique properties of the 01+ → 41+ transition. In the inelastic scattering to the 41+ state, the dominant two-step process of the 01+→ 21+→ 41+ transitions and the deconstructive interference in the weak one-step process were essential.