QUARTETTING IN NUCLEAR MATTERAND a PARTICLE CONDENSATION IN NUCLEAR SYSTEMS

摘要

Alternatively to pairing, four-particle correlations may become of importance for the for-mation of quantum condensates in nuclear matter. With increasing density, four-particlecorrelations are suppressed because of Pauli blocking. Signatures of a-like clusters areexpected to occur in low-density nuclear systems. The famous Hoyle state (02+ at 7.654MeV in 12C) is identified as being an almost ideal condensate of three a-particles, holdtogether only by the Coulomb barrier. It, therefore, has a 8Be-ct structure of low density.Transition probability and inelastic form factor together with position and other physi-cal quantities are correctly reproduced without any adjustable parameter from our twoparameter wave function of a-particle condensate type. The possibility of the existenceof a-particle condensed states in heavier na nuclei is also discussed.