Spins of the levels and multipole mixing ratios of transitions in 125Sb determined from γ-γ directional correlation and polarization-directional correlation measurements

Abstract

Abstract In order to resolve several discrepancies in spin assignments to levels in 125 Sb, directional correlations and polarization-directional correlations have been measured for several γ-γ cascades in 125 Sb populated from the decay of 125 Sn. Earlier results obtained from using NaI and Ge(Li) and NaI detectors were difficult to interpret due to the complex structure of the decay scheme. To improve the experimental situation, we have used two coaxial Ge(Li) detectors for the angular correlation measurements and a coaxial Ge(Li)-planar Ge(Li) combination for the polarization-directional correlations. Combination of the results of these measurements give unique spin assignments of 11 2 − , 11 2 − , 9 2 + , 11 2 + and 9 2 + to the 1982 keV, 1890 keV, 1420 keV, 1089 keV and 1067 keV levels, respectively. The determined E2/M1 mixing ratios are : δ (470) = 0.010±0.027, δ (1067) = −0.86±0.18, and δ (916) = −0.02±0.01.