On Nd, Sm and other unexplored 2 decay isotopes
arXiv:1709.08735 · doi:10.1103/PhysRevC.97.015501
Abstract
Nd is one of only four (over a total of 35 existing) 2 decay isotope candidates whose half-lives currently lack experimental limits. The activity of the Sm daughter nuclide allows placement of limits on the 2 decay using the Nd/Nd abundance ratio ($T^{ββ}_{1/2} \gsim 3 \times 10^9$ yr) or direct search for Sm with accelerator mass spectrometers ($T^{ββ}_{1/2} \gsim 4.5 \times 10^{19}$ yr). With a similar approach, a modest ( Gyr) first limit on half-lives for the other unexplored unstable isotopes and competitive limits (few yr) for Mo and Sn are also given. Finally, it is shown how the limit $T^{0νεβ^+}_{1/2} \gsim 10^{15}$ yr for the unexplored Sm decay may be obtained from the data of a GSO crystal scintillator.
5 pages, 1 figure