title: alpha-particle condensation in 16O studied with a full four-body orthogonality condition model calculation.
abstract: To explore the four-alpha-particle condensate state in 16O, we solve a full four-body equation of motion based on the four-alpha-particle orthogonality condition model in a large four-alpha-particle model space spanned by Gaussian basis functions. A full spectrum up to the 0_{6};{+} state is reproduced consistently with the lowest six 0;{+} states of the experimental spectrum. The 0_{6};{+} state is obtained at about 2 MeV above the four-alpha-particle breakup threshold and has a dilute density structure, with a radius of about 5 fm. The state has an appreciably large alpha condensate fraction of 61%, and a large component of alpha+12C(0_{2};{+}) configuration, both features being reliable evidence for this state to be of four-alpha-particle condensate nature.
authors.affiliation: Nishina Center for Accelerator-Based Science, The Institute of Physical and Chemical Research (RIKEN), Wako 351-0198, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Funaki
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: H
authors.initials: H
authors.lastname: Horiuchi
authors.forename: G
authors.initials: G
authors.lastname: Röpke
authors.forename: P
authors.initials: P
authors.lastname: Schuck
authors.forename: A
authors.initials: A
authors.lastname: Tohsaki