${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ $\gamma$ rays following ${}_{}{}^{20}{}_{}{}^{}\mathrm{Na}$ decay identified new branches to states at 9.87, 10.88, and 11.26 MeV, as well as known branches to states at 1.63 and 10.27 MeV. Branching ratios and $\mathcal{F}t$ values based on these observations are compared to nuclear structure calculations, and the ${\beta }^{\pm }$ $\mathcal{F}t$ asymmetry for $A=20\mathrm{}$ is discussed.

RADIOACTIVITY ${}_{}{}^{20}{}_{}{}^{}\mathrm{Na}$ [from ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}\mathrm{}(p,n)\mathrm{}$, $E=22.9\mathrm{}$ MeV]; measured $E_{\gamma }$, $I_{\gamma }$; deduced ${\beta }^{+}$ branching ratios, $\mathcal{F}t$ values, ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ levels $J^{\pi }$, mirror ${\beta }^{+}$ asymmetry; enriched target; Ge(Li) detector.

• Received 5 April 1976

DOI:https://doi.org/10.1103/PhysRevC.14.254