Observation of an Excited State in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>H</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow/><mml:mrow><mml:mn>7</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow><mml:mi>e</mml:mi></mml:math>with Unusual Structure

The transfer reaction $p{(}^{8}\mathrm{He},d{)}^{7}\mathrm{He}$ has been studied by correlational measurements, and an excited state of ${}^{7}\mathrm{He}$ was observed ( ${E}^{*}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}2.9\ifmmode\pm\else\textpm\fi{}0.3\mathrm{MeV}$, $\ensuremath{\Gamma}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}2.2\ifmmode\pm\else\textpm\fi{}0.3\mathrm{MeV}$) which decays mainly into ${3n+}^{4}\mathrm{He}$. Most likely, it has a structure with a neutron in an excited state coupled to the ${}^{6}\mathrm{He}$ core which itself is in the excited ${2}^{+}$ state.