Analysis of the Beta Spectrum and Branching inHo166

Abstract
The shape of the β spectrum of the Ho166Er166 ground state (0- → 0+) transition and the branching to the first excited state (2+) has been investigated. Corrections due to the variation of the lepton wave functions over the nucleus have also been taken into account, and it is shown that under certain conditions these corrections can be sufficient to explain the experimental findings.