$R$-matrix formulas are used to calculate the two-proton decay widths of the ${}^6\mathrm{Be}$ and ${}^8\mathrm{C}$ ground states and of the ${}^6\mathrm{Be}$ first excited state. The calculated widths for the ${}^6\mathrm{Be}$ states depend strongly on the values taken for the energy and width of the ${}^5\mathrm{Li}$ ground state; agreement for the ${}^6\mathrm{Be}$ ground-state width can be obtained for a reasonable choice $\mathrm{of}{\hspace{0.5em}}^5\mathrm{Li}$ parameter values, and the same choice gives good agreement for $\mathrm{the}{\hspace{0.5em}}^6\mathrm{Be}$ excited-state width and branching ratio for ${}^2\mathrm{He}$ decay. For ${}^8\mathrm{C},$ contributions from two of the possible decay channels give an appreciable fraction of the experimental width.

• Received 1 May 2002

DOI:https://doi.org/10.1103/PhysRevC.66.047603