1. Multi-cluster dynamics inCΛ13and analogy to clustering in 12 C
- Author
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Emiko Hiyama, M. Isaka, Y. Funaki, Taiichi Yamada, and Kiyomi Ikeda
- Subjects
Physics ,Nuclear and High Energy Physics ,010308 nuclear & particles physics ,Compact star ,Hypernucleus ,01 natural sciences ,Spectral line ,medicine.anatomical_structure ,Excited state ,Quantum mechanics ,0103 physical sciences ,Bound state ,medicine ,Cluster (physics) ,Atomic physics ,010306 general physics ,Wave function ,Nucleus - Abstract
We investigate structure of C Λ 13 and discuss the difference and similarity between the structures of C 12 and C Λ 13 by answering the questions if the linear-chain and gaslike cluster states, which are proposed to appear in C 12 , survives, or new structure states appear or not. We introduce a microscopic cluster model called, Hyper-Tohsaki–Horiuchi–Schuck–Ropke (H-THSR) wave function, which is an extended version of the THSR wave function so as to describe Λ hypernuclei. We obtained two bound states and two resonance (quasi-bound) states for J π = 0 + in C Λ 13 , corresponding to the four 0 + states in C 12 . However, the inversion of level ordering between the spectra of C 12 and C Λ 13 , i.e. that the 0 3 + and 0 4 + states in C Λ 13 correspond to the 0 4 + and 0 3 + states in C 12 , respectively, is shown to occur. The additional Λ particle reduces sizes of the 0 2 + and 0 3 + states in C Λ 13 very much, but the shrinkage of the 0 4 + state is only a half of the other states, in spite of the fact that attractive Λ-N interaction makes nucleus contracted so much when the Λ particle occupies an S-orbit. In conclusion, the Hoyle state becomes quite a compact object with Be Λ 9 + α configuration in C Λ 13 and is no more gaslike state composed of the 3α clusters. Instead, the 0 4 + state in C Λ 13 , coming from the C 12 ( 0 3 + ) state, appears as a gaslike state composed of α + α + Λ 5 He configuration, i.e. the Hoyle analog state. A linear-chain state in a Λ hypernucleus is for the first time predicted to exist as the 0 3 + state in C Λ 13 with more shrunk arrangement of the 3α clusters along z-axis than the 3α linear-chain configuration realized in the C 12 ( 0 4 + ) state. All the excited states are shown to appear around the corresponding cluster-decay threshold, reflecting the threshold rule.
- Published
- 2017
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