Showing papers by "Ken-Ichi Fushimi published in 2004"

Trinucleon cluster structures in Li 6

Abstract: The $t+^{3}\mathrm{He}$ cluster structures in $^{6}\mathrm{Li}$ were investigated by using the $^{7}\mathrm{Li}(^{3}\mathrm{He},\ensuremath{\alpha})$ reaction at $450\phantom{\rule{0.3em}{0ex}}\text{MeV}$ and at ${\ensuremath{\theta}}_{L}=0\ifmmode^\circ\else\textdegree\fi{}$. A binary decay into $t+^{3}\mathrm{He}$ with a branching ratio of $0.8\ifmmode\pm\else\textpm\fi{}0.2$ from a broad state at ${E}_{x}=21\phantom{\rule{0.3em}{0ex}}\text{MeV}$ in $^{6}\mathrm{Li}$ was observed by measuring $t$ and $^{3}\mathrm{He}$ decay particles. From the measured angular correlations and with the analysis of the spectral shape by using the Breit-Wigner formula, the $21\text{\ensuremath{-}}\text{MeV}$ resonance was decomposed into the $^{1}P$ $(T=0)$ state at ${E}_{x}=18.0\ifmmode\pm\else\textpm\fi{}0.5\phantom{\rule{0.3em}{0ex}}\text{MeV}$ with $\ensuremath{\Gamma}(\text{FWHM})=5.0\ifmmode\pm\else\textpm\fi{}0.5\phantom{\rule{0.3em}{0ex}}\text{MeV}$ (where FWHM means full width at half maximum), and the $^{3}P$ $(T=1)$ state at ${E}_{x}=22\ifmmode\pm\else\textpm\fi{}1\phantom{\rule{0.3em}{0ex}}\phantom{\rule{0.3em}{0ex}}\text{MeV}$ with $\ensuremath{\Gamma}=8\ifmmode\pm\else\textpm\fi{}1\phantom{\rule{0.3em}{0ex}}\text{MeV}$.

Trinucleon Cluster Structure at High-Excitation Energies in A = 6 Nuclei

Abstract: Trinucleon molecular structures in 6He and 6Be were investigated by using the 6Li(7Li, 7Be)6He reaction at 455 MeV and 6Li(3He, t)6Be reaction at 450 MeV, respectively. Binary decays into t + t from a broad state at Ex=18.0±1.0 MeV in 6He and into 3He + 3He from one at Ex=18.0±1.2 MeV in 6Be, respectively, were observed by measuring trinucleon cluster decays in coincidence with reaction particles. The branching ratios for binary decay were estimated to be about 0.7 for 6He and 6Be. These large branching ratios show that a trinucleon cluster state exists as an isobaric partner around Ex=18 MeV in 6He and 6Be.