4$α$ linear-chain state produced by $^{9}$Be+$^{9}$Be collision

Abstract: Extreme nuclear deformations provide great insight into the geometric formation of quantum many-body systems. In this work, the $4\alpha+2n$ linear chain is assessed in $<sup>{18}$O. We predict excitation energies, moment-of-inertia, $\alpha$-, and $<sup>{9}$Be-decay widths by using the antisymmetrized molecular dynamics. We show that the $K<sup>\pi=3<sup>-$ linear-chain states may be verified by the head-on $^{9}{\rm Be}+{}^{9}{\rm Be}$ collision experiments.