Updated evaluation of potential ultralow Q-value?-decay candidates

Ultralow Q-value 0 decays are referred to as such due to their low decay energies of less than approximate to 1 keV. Such a low energy decay is possible when the parent nucleus decays to an excited state in the daughter, with an energy close to that of the Q value. These decays are of interest as potential new candidates for neutrino mass determination experiments and as a testing ground for studies of atomic interference effects in the nuclear decay process. In this paper, we provide an updated evaluation of atomic mass data and nuclear energy-level data to identify potential ultralow Q-value 0-decay candidates. For many of these candidates, more precise and accurate atomic mass data is needed to determine if the Q value of the potential ultralow decay branch is energetically allowed and in fact ultralow. The relevant precise atomic mass measurements can be achieved via Penning trap mass spectrometry.

Automated summary

Ultralow Q-value 0 decays refer to decays with energies less than approximately 1 keV. These decays occur when the parent nucleus decays to an excited state in the daughter nucleus with an energy close to the Q value. They are of interest for neutrino mass determination experiments and atomic interference effects in nuclear decay. This paper provides an updated evaluation of atomic mass and nuclear energy-level data to identify potential ultralow Q-value 0 decay candidates. Precise atomic mass measurements using Penning trap mass spectrometry are needed for further study.