The following lifetimes have been measured: ${\mathrm{O}}^{17}$ 870-kev level, (2.5±1)×${10}^{-10\mathrm{}}$ sec; ${\mathrm{B}}^{10}$ 720-kev level, (7±2)×${10}^{-10\mathrm{}}$ sec. These values are compared with theoretical estimates based on the independent-particle model. Core excitation is required to explain the ${\mathrm{O}}^{17}$ lifetime.

• Received 24 August 1953

DOI:https://doi.org/10.1103/PhysRev.92.1253