Be8and α decay ofO16

The ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ ${(}^{16}$O,4α${)}^{12}$C reaction has been studied at a beam energy of 99 MeV. The data indicate the existence of sequential decays in the form ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}_{}^{\mathrm{*}}{}_{}{}^{}$→4α in the exit channel. The excitation energy of the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ nucleus and the nature of the partition process leading to the 4α final state, has been reconstructed from the kinematics of the α particles. States have been observed at excitation energies of 17.1, 17.5, 18.0, 18.7, 19.3, and 21.4 MeV which decay into ${}_{}{}^8{}_{}{}^{}\mathrm{Be}$ ${+}^8$Be, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(7.65 MeV, $0_2^{+}$)+α and ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(9.64 MeV, $3^{\mathrm{-}}$)+α. Relative partial decay widths for these three channels have been measured. Angular correlation measurements have been used to deduce the spins of several of the observed states, and indicate spins in the range 2 to 6ħ.