Article

Proton halo of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">B</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow/><mml:mrow><mml:mn>8</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow></mml:math>disclosed by its giant quadrupole moment

T. MinamisonoDepartment of Chemistry, Faculty of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560, JapanT. OhtsuboDepartment of Chemistry, Faculty of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560, JapanI. MinamiDepartment of Chemistry, Faculty of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560, JapanS. FukudaDepartment of Chemistry, Faculty of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560, JapanA. KitagawaDepartment of Chemistry, Faculty of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560, JapanMitsunori FukudaDepartment of Chemistry, Faculty of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560, JapanK. MatsutaDepartment of Chemistry, Faculty of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560, JapanY. NojiriDepartment of Chemistry, Faculty of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560, JapanS. TakedaDepartment of Chemistry, Faculty of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560, JapanH. SagawaDepartment of Chemistry, Faculty of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560, JapanH. KitagawaDepartment of Chemistry, Faculty of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560, Japan

1992lv

ABI

Abstract

The quadrupole moment of the $^{8}\mathrm{B}$ (${\mathit{I}}^{\mathrm{\ensuremath{\pi}}}$=${2}^{+}$, ${\mathit{T}}_{1/2}$=769 msec) nucleus was measured as \ensuremath{\Vert}Q${(}^{8}$B)\ensuremath{\Vert}=68.3\ifmmode\pm\else\textpm\fi{}2.1 mb by use of modified \ensuremath{\beta}-NMR. This value is twice as large as the prediction of the Cohen-Kurath shell model. It is found by subtracting the contribution of deeply bound neutrons that the protons in $^{8}\mathrm{B}$ carry more than 90% of the observed moment. The anomalous value is accounted for fairly well by the proton halo due to the loosely bound valence configuration. This is the first experimental evidence for the existence of a proton halo covering a neutron core.

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Identifiers

DOI: 10.1103/physrevlett.69.2058

Citations and references

Cited by 30 references

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