Proton Inelastic Scattering on Island-of-Inversion Nuclei

Abstract

The quadrupole collectivity of 28,30 Ne and 32,34,36 Mg, which are located around the conventional magic number of N = 20, was studied via proton inelastic scattering with a liquid hydrogen target by in-beam γ-ray spectroscopy in inverse kinematics. The deformation lengths were extracted from the angle-integrated cross sections for the first 2 + states using distorted-wave calculations. We have determined the deformation length of 36 Mg to be 1.90 +0.16 −0.17 fm for the first time. For 34 Mg and 30 Ne, the accuracies were improved. The evolution of quadrupole deformation in the vicinity of 32 Mg is discussed by comparing the present results with the theoretical calculations.