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Author Yamada, Taiichi ♦ Funaki, Yasuro
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword NUCLEAR PHYSICS AND RADIATION PHYSICS ♦ BORON 11 ♦ CARBON 12 ♦ CONDENSATES ♦ CONFIGURATION ♦ ENERGY LEVELS ♦ EXPANSION ♦ ISOBARIC ANALOGS ♦ LITHIUM 7 ♦ MEV RANGE 10-100 ♦ PARITY ♦ PROBABILITY ♦ SCALING ♦ SHELL MODELS ♦ SIMULATION ♦ BORON ISOTOPES ♦ CARBON ISOTOPES ♦ ENERGY RANGE ♦ EVEN-EVEN NUCLEI ♦ ISOTOPES ♦ LIGHT NUCLEI ♦ LITHIUM ISOTOPES ♦ MATHEMATICAL MODELS ♦ MEV RANGE ♦ NUCLEAR MODELS ♦ NUCLEI ♦ ODD-EVEN NUCLEI ♦ PARTICLE PROPERTIES ♦ STABLE ISOTOPES
Abstract The structure of 3/2{sup -} and 1/2{sup +} states in {sup 11}B is investigated with an {alpha}+{alpha}+t orthogonality condition model (OCM) based on the Gaussian expansion method. Full levels up to the 3/2{sub 3}{sup -} and 1/2{sub 2}{sup +} states around the {alpha}+{alpha}+t threshold (E{sub x}=11.1 MeV) are reproduced consistently with the experimental energy levels. It is shown that the 3/2{sub 3}{sup -} state located around the {sup 7}Li+{alpha} threshold has an {alpha}+{alpha}+t cluster structure, whereas the 3/2{sub 1}{sup -} and 3/2{sub 2}{sup -} states have a shell-model-like compact structure. We found that the 3/2{sub 3}{sup -} state does not possess an {alpha}-condensate-like nature analogous to the 0{sub 2}{sup +} state of {sup 12}C (Hoyle state) which has a dilute 3{alpha}-condensate structure described by a (0S{sub {alpha}}){sup 3} configuration with about 70% probability, although the monopole transition strength of the former is as large as that of the latter. We discuss the reasons why the 3/2{sub 3}{sup -} state does not have the condensate character. On the other hand, the 1/2{sub 1}{sup +} state just below the {sup 7}Li+{alpha} threshold has a cluster structure that can be interpreted as a parity-doublet partner of the 3/2{sub 3}{sup -} state. We indicate that the 12.56-MeV state (J{sup {pi}}=1/2{sub 2}{sup +}) just above the {alpha}+{alpha}+t threshold observed in the {sup 7}Li({sup 7}Li,{sup 11}B{sup *})t reaction, etc., is of the dilute cluster-gas-like configuration and is a strong candidate for the product states of clusters, having a configuration of (0S{sub {alpha}}){sup 2}(0S{sub t}) with about 65% probability, from the analyses of the single-cluster motions in {sup 11}B. The structure property of the 1/2{sup +} resonant state is analyzed with the complex scaling method.
ISSN 05562813
Educational Use Research
Learning Resource Type Article
Publisher Date 2010-12-15
Publisher Place United States
Journal Physical Review. C, Nuclear Physics
Volume Number 82
Issue Number 6


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