2alpha+t cluster feature of $3/2_3^{-}$ state in ${}^{11}$B

Abstract

We reanalyze $2\alpha +t$ cluster features of $3/2^{-}$ states in ${}^{11}$B by investigating the $t$ cluster distribution around a $2\alpha$ core in ${}^{11}$B, calculated with the method of antisymmetrized molecular dynamics (AMD). In the $3/2_3^{-}$ state, a $t$ cluster is distributed in a wide region around $2\alpha$, indicating that the $t$ cluster moves rather freely in angular as well as radial motion. From the weak angular correlation and radial extent of the $t$ cluster distribution, we propose an interpretation of a $2\alpha +t$ cluster gas for the $3/2_3^{-}$ state. In this study, we compare the $2\alpha +t$ cluster feature in ${}^{11}$B($3/2_3^{-}$) with the $3\alpha$ cluster feature in ${}^{12}$C($0_2^{+}$), and discuss their similarities and differences.

Comments: 14 pages, 11 figures