Alpha-cluster Formation and Decay: Four-Body Correlation and Configuration Mixing

RESUMO

Alpha-decay provides an important probe of nuclear structure and the underlying nucleon-nucleon interaction, while its rigorous microscopic description from first principles remains challenging. For $\alpha$+magic core systems, a microscopic treatment of $\alpha$-cluster formation and decay has been achieved by considering both the four-body correlation on top of the core and Pauli blocking. Extending this microscopic description to open-shell nuclei should account for the configuration mixing caused by the residual interactions between valence nucleons near the Fermi surface. In this work, we improve the quartetting wave function approach (QWFA) by incorporating the pairing-induced configuration mixing using the particle-number-projected Bardeen-Cooper-Schrieffer (PBCS) method. We find that the pairing enhance the formation amplitudes of the $\alpha$-cluster in open-shell nuclei while the closed shells suppress the $\alpha$-clustering.