Measurement of -Transition Lifetimes by Recoil Methods III: E2 Transitions in some Even-Even Nuclei

The mean lives of the first 2+ states of 12C, 16O, 20Ne, and 28Si have been measured using recoil methods with following results: 12C τ = 2.6 ± 0.9 × 10-14sec. 16O τ less, similar 2.5 × 10-14sec. 20Ne τ = 7.6 ± 3.3 × 10-13sec. 28Si 9 × 10-13 less, similar τ (or τ less, similar 3 × 10-14).