Approximation of reduced width amplitude and application to cluster decay width

Abstract

We propose a simple method to approximately evaluate reduced width amplitude (RWA) of a two-body spinless cluster channel using the norm overlap with the Brink-Bloch cluster wave function at the channel radius. The applicability of the present approximation is tested for the ${}^{16}$O+$\alpha$ channel in ${}^{20}$Ne as well as the $\alpha$+$\alpha$ channel in ${}^8$Be. The approximation is found to be reasonable to evaluate the RWA for states near the threshold energy and it is useful to estimate the $\alpha$-decay width of resonance states. The approximation is also applied to ${}^9$Li, and the partial decay width of the ${}^6$He($0_1^{+}$)+$t$ channel is discussed.

Comments: 20 pages, 10 figures