Alpha Cluster States and Condensation in ^{16}O

Low density states near the 4α breakup threshold in ^{16}O is discussed in terms of the α-particle condensation. Calculations are performed with OCM (Orthogonality Condition Model) and GEM (Gauss Expansion Method). The 0_6^+ state in ^{16}O is shown to have a character of the 4α condensate, as an analogue to the Hoyle state in ^{12}C. The decay property of the s tate and the α + Hoyle-like rotatinal states are also investigated.