Investigation of the 4-αlinear chain state in16O

Abstract

The ${}^{12}$C(${}^{4}$He,${}^{8}$Be)${}^{8}$Be and ${}^{12}$C(${}^{4}$He,${}^{12}$C${}^{*}$ $\ensuremath{\rightarrow}$ ${}^{8}$Be+$\ensuremath{\alpha}$)$\ensuremath{\alpha}$ reactions have been measured with beam energies ranging from 12.2 to 20.0 MeV. The $\ensuremath{\alpha}$ particles emitted directly and following the decay of ${}^{8}$Be and ${}^{12}$C${}^{*}$ were detected in an array of four double sided silicon strip detectors. An analysis of the angular distributions obtained for the ${}^{12}$C(${}^{4}$He,${}^{8}$Be)${}^{8}$Be channel provides no evidence to support the previously proposed rotational structure consisting of a rigid, linear, arrangement of four $\ensuremath{\alpha}$ particles in ${}^{16}$O.