A new determination of the mass excess of ${}_{}{}^8{}_{}{}^{}\mathrm{C}$ by the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(${}_{}{}^4{}_{}{}^{}\mathrm{He}$, ${}_{}{}^8{}_{}{}^{}\mathrm{He}$)${}_{}{}^8{}_{}{}^{}\mathrm{C}$ reaction has yielded a value of 35.10 ± 0.03 MeV. The new value is in good agreement with the quadratic isobaric multiplet mass equation prediction. Higher order cubic and quartic mass equation coefficients are found to be small for the $A=8\mathrm{}$ isobaric quintet.

NUCLEAR REACTIONS ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(${}_{}{}^4{}_{}{}^{}\mathrm{He}$, ${}_{}{}^8{}_{}{}^{}\mathrm{He}$). Measured ${}_{}{}^8{}_{}{}^{}\mathrm{C}$ mass. Deduced coefficients of the isobaric multiplet mass equation for the $A=8\mathrm{}$ quintet.

• Received 14 October 1975

DOI:https://doi.org/10.1103/PhysRevC.13.50