New experimental limits on the electron stability and excitation of nuclear levels in 23Na, 127I and129Xe induced by the electron decay on the atomic shell

The background measurements have been performed in the Gran Sasso National Laboratory of INFN with the help of the large mass highly radiopure ≅ 100 kg DAMA NaI(Tl) set-up (34866 kg · day statistics) and the ≅ 6.5 kg liquid Xenon DAMA scintillator set-up (2257.7 kg · day). New lifetime limits on the charge nonconserving (CNC) electron decays have been established: τ(e- → νeν bareνe) > 4.2(2.4) · 1024 y and τ(e- → νeγ) > 3.4(2.0) · 1026 y at 68% (90%) C.L. Lifetime limits on the CNC electron capture with nuclear levels excitation of 23Na, 127I, and 129Xe are also established; they are in the range τ > 1.5 · 1023 - 4 · 1024 y. All limits are at least few times higher than the ones previously available