On the β-Transition of ²⁰⁵T1 to ²⁰⁵Pb

Abstract

Some first forbidden β-decays in nuclei near ²⁰⁸ Pb have low ft-values. The large matrix elements corresponding to these were interpreted long ago as due to purity of shell model configurations at the closed proton and neutron shells [1]. On the basis of this information it was suggested to build a low energy neutrino detector [2]. A neutrino with energy higher than 62 keV could be absorbed by ²⁰⁵ Tl nucleus in its 1/2⁺ ground state resulting in a 1/2^- state, 2.3 keV above the ²⁰⁵ Pb ground state.