723 keV beta transition in the negatron decay of 122Sb

The energy dependence of the angular correlation of the cascade 2-(723 keV β particle) 2+(1260 keV γ ray)0+ in the decay of 122Sb is measured and found to agree with the reports of Raghavan et al. and Yamada et al. Nuclear matrix elements governing the 723 keV β transition are extracted using the available experimental data on this transition. Buhring's formulas that are simplified by Simms are used in the analysis. It is observed that the contribution of the nondiagonal elements to the Coulomb Hamiltonian is significant