Neutron-Deficient Members of the $A=139\mathrm{}$ Decay Chain. I. 5.5-h ${\mathrm{Nd}}^{139m}$ and 30-min ${\mathrm{Nd}}^{139g}$

We have studied the $\gamma$ rays emitted following the decays of 5.5-h ${\mathrm{Nd}}^{139m}$ and 30-min ${\mathrm{Nd}}^{139g}$ with Ge (Li) and NaI (T1) detectors in singles, coincidence, and anticoincidence configurations. Our study has indicated 51 $\gamma$ rays accompanying ${\mathrm{Nd}}^{139m}$ decay and 21 that follow ${\mathrm{Nd}}^{139g}$ decay. Of these, 56 have been placed in decay schemes containing a total of 22 excited states. The decay scheme of $\frac{3}{2}+{\mathrm{Nd}}^{139g}$ has much in parallel with those of similar nuclei in this region, and states are populated in ${\mathrm{Pr}}^{139}$ at $0 (\frac{5}{2}+)$, $113.8 (\frac{7}{2}+)$, $405.0 (\frac{3}{2}+,\frac{1}{2}+)$, $589.2 (\frac{5}{2}+)$, $916.8 (\frac{1}{2}+,\frac{3}{2}+)$, $1074.4 (\frac{1}{2}+,\frac{3}{2}+)$, $1311.8 (\frac{1}{2}+,\frac{3}{2}+,\frac{5}{2}+)$, $1328.2 (\frac{5}{2}+)$, $1405.5 (\frac{1}{2}+,\frac{3}{2}+,\frac{5}{2}+)$, $1449.5 (\frac{1}{2}+,\frac{3}{2}+,\frac{5}{2}+)$, and $1501.2 \mathrm{keV}(\frac{1}{2}+,\frac{3}{2}+)$. On the other hand, 11/2- ${\mathrm{Nd}}^{139m}$ decays only 12.7% via a 231.2-keV $M4\mathrm{}$ isomeric transition and independently decays by electron capture to a set of almost completely different states in ${\mathrm{Pr}}^{139}$. These are at $0 (\frac{5}{2}+)$, $113.8 (\frac{7}{2}+)$,