Search for Members of the Two-Phonon Triplets inSe80andKr80

The $\gamma$ rays emitted in the decay of ${}_{}{}^{80}{}_{}{}^{}\mathrm{Br}$ have been investigated with Ge(Li) and NaI(Tl) spectrometers. $\gamma$ rays (relative intensities are in parentheses) of 616.2±0.5(100), 639.2±0.7(3.6), 665.6±0.5(17.2), 704.0±0.7(2.9), 812.0±1.5(0.8), and 1256.4±1.5(1.0) keV have been observed. Coincidence and $\gamma -\gamma$ directional correlation measurements were performed with two NaI detectors, a fast coincidence system, and a multiparameter analyzer to record the data. The coincidence studies indicated levels at 616.2±0.5, 1255.6±0.6, and 1320.2±0.9 keV in ${}_{}{}^{80}{}_{}{}^{}\mathrm{Kr}$, and 665.6±0.5 and 1477.6±1.6 keV in ${}_{}{}^{80}{}_{}{}^{}\mathrm{Se}$. The experimental directional correlation coefficients of the 639.2-616.2-keV, 704.0-616.2-keV, and 812.0-665.6-keV cascades are $A_2=-(0.12\mathrm{}\pm 0.04)$, $A_4=+(0.38\mathrm{}\pm 0.10)$; $A_2=+(0.38\mathrm{}\pm 0.06)$, $A_4=+(1.28\mathrm{}\pm 0.18)$; and $A_2=+(0.29\mathrm{}\pm 0.13)$, $A_4=+(1.32\mathrm{}\pm 0.37)$, respectively. These values are compatible with spin assignments of $0^{+}$ for the 1477.6-keV level in ${}_{}{}^{80}{}_{}{}^{}\mathrm{Se}$, and of $2^{+}$ and $0^{+}$ for the 1255.6- and 1320.2-keV ${}_{}{}^{80}{}_{}{}^{}\mathrm{Kr}$ levels, respectively.