Fig. 1: Decay diagram from the 137Cs ground state to the 137Ba ground state.
From: Electromagnetic character of the competitive γγ/γ-decay from 137mBa
Illustration of the single-γ and the two types of double-γ decay, as fed by the β decay of 137Cs, including half lives of 137Cs and 137mBa. The energy of the 137Cs ground state (Qβ) is given relative to the 137Ba ground state. Here, M4 corresponds to the single-photon decay. The blue and pink decays show the lowest octupole-dipole and quadrupole–quadrupole components, respectively.
