Alpha-decay from 44Ti: A study of the microscopic clusterization

Abstract

Background: Microscopic determination of alpha-decay half-lives requires structure and reaction calculations. The structure part is given by the microscopic distribution of the constituent nucleons, while the relative motion of the product´s decay provides the reaction part. Purpose: This paper studies the clusterization of the 0+ excited states of Ti44 arising from the nucleonic degrees of freedom. Methods: The continuum spectra of proton and neutron are incorporated through the Gamow shell-model formalism. The alpha-like wave function is calculated in the weak-coupling approximation. Gaussian effective interaction in each pair of nucleons is included. Results: The 0+ ground and excited states are compared with experiment and shell-model calculations. The wave-function amplitudes are obtained and discriminated by their resonant and nonresonant contributions. The influence of a four-body truncated basis is analyzed. Conclusions: Inclusion of the continuum spectra produces a gain in the excited states of a few hundred keV of energy. One candidate for alpha decay was identified near the experimental unresolved state (0,2)+ of 6.8 MeV excitation energy, with a lower limit for the half-life of ≈0.8 ns.