https://doi.org/10.1140/epja/s10050-019-00003-z
Regular Article - Theoretical Physics
Overlap of electron shells in 
and double- decays
1
Institute for Theoretical and Experimental Physics, National Research Center “Kurchatov Institute”, B. Cheremushkinskaya 25, 117218, Moscow, Russia
2
National Research Center “Kurchatov Institute”, pl. Kurchatova 1, 123182, Moscow, Russia
* e-mail: mikhail.krivoruchenko@itep.ru
Received:
10
July
2019
Accepted:
26
October
2019
Published online:
21
January
2020
The and double- decay channels, which are not accompanied by excitation of the electron shells, are suppressed due to the nonorthogonality of the electron wave functions of the parent and daughter atoms. The effect is sensitive to the contribution of the outer electron shells. Since valence electrons participate in chemical bonding and collectivize in metals, the decay rates of the unstable nuclides are modified when they are embedded in a host material. Core electrons are less affected by the environment, and their overlap amplitudes are more stable. The suppression effect is estimated for 
decay of 
Kr, electron capture in 
Ho, and 
decays of 
Ge, 
Mo, 
Te, and 
Xe. The overlap amplitude of the electron shells enters the relationship between the half-life of neutrinoless 
decay and the effective electron neutrino Majorana mass.
© Società Italiana di Fisica (SIF) and Springer-Verlag GmbH Germany, part of Springer Nature, 2020
