Double electron capture in 156Dy, 162Er and 168Yb

The double electron capture half-lives of 156Dy, 162Er and 168Yb are evaluated using the pseudo SU(3) model, which describes ground and excited bands as well as their B(E2) and B(M1) transition strengths in remarkable agreement with experiment. The best candidate for experimental detection is the decay 156Dy → 156Gd, with τ1/2(0+gs→0+gs)=2.74×1022 yrs and τ1/2(0+gs→0+1)=8.31×1024 yrs.