부산대학교 도서관

Precise estimation of the rare direct 3α decay of the Hoyle state of 12C has been made to unveil its unusual α-cluster configurations ranging from linear 3α chain structure to diffuse Bose gas as well as Bose Einstein condensate. The present new high precision, nearly zero background experimental study with 1.6×105 Hoyle events has converged on the upper limit for direct decay at ∼0.019% with 95% confidence limit, which is more than a factor of 2 lower than the limit obtained in the previous studies. Keywords: 3α cluster state, 12C(α, α)3α reaction, Complete kinematics reaction, The Hoyle state decay, Direct versus sequential decay, Inelastic scattering