Systematics of the α decay to vibrational2+states

Abstract

We give a systematic analysis of \ensuremath{\alpha} decays to low-lying ${2}^{+}$ states in even-even nuclei. Collective excitations are considered within the spherical quasiparticle random-phase approximation. We use realistic G-matrix elements of the Bonn interaction as a residual two-body force. The only free parameters are the ratio between the isovector and isoscalar strengths and proton-neutron asymmetry. The formalism can reproduce the main experimental trends versus the excitation energy for both the $B(E2)$ values and the \ensuremath{\alpha}-decay hindrance factors. We reproduced most of the available data by using one common parametrization. It turns out that the fine structure of the \ensuremath{\alpha} decay is more sensitive than electromagnetic transitions as a tool for investigating nuclear interaction. With the adopted parametrization, we predict $B(E2)$ values and \ensuremath{\alpha}-decay hindrance factors in even-even nuclei.