The mean life of the first excited state of ${\mathrm{N}}^{14}$ has been measured by nuclear resonant scattering. The ${\mathrm{N}}^{14}(p, p^{\prime })$ reaction with an ${\mathrm{N}}^{14}$ enriched gaseous ammonia target was used as the source of Doppler-broadened $\gamma$ radiation. The value of (7.3±1.8)×${10}^{-14\mathrm{}}$ sec obtained is a factor of two longer than theoretical predictions based on the wave functions used to explain the anomalously slow ${\mathrm{C}}^{14}$ $\beta$ decay.

• Received 26 August 1960

DOI:https://doi.org/10.1103/PhysRev.121.242