Searching for 4$\alpha$ linear-chain structure in excited states of $^{16}$O with a covariant density functional theory

摘要

A study of 4$\alpha$ linear-chain structure in high-lying collectiveexcitation states of $^{16}$O with a covariant density functional theory ispresented. The low-spin states are obtained by configuration mixing ofparticle-number and angular-momentum projected quadrupole deformed mean-fieldstates with generator coordinate method. The high-spin states are determined bycranking calculations. These two calculations are based on the same energydensity functional PC-PK1. We have found a rotational band at low-spin with thedominated intrinsic configuration considered to be the one that 4$\alpha$clusters stay along a common axis. The strongly deformed rod shape also appearsin the high-spin region with the angular momentum $13-18\hbar$; however whetherthe state is pure $4\alpha$ linear chain or not is less obvious than that inthe low-spin states.