Abstract
In this work we perform a systematic study of pairs of single--decaying nuclei in the mass region to extract information on the effective value of the axial-vector coupling constant . As the many-body framework we use the quasiparticle random-phase approximation (QRPA) and its proton-neutron variant (pnQRPA) in single-particle valence bases with Woods-Saxon-calculated single-particle energies. It is found that, to a reasonable approximation, is a linear function of the mass number , with a slightly different parametrization below and above the mass . Using the values of extracted from the linear fit, as well as an average constant value of , we calculate the two-neutrino double- () decay half-lives of 11 decays and 10 mixed and electron-capture (EC) decays, , to both the ground state and the lowest three excited states.
5 More- Received 16 January 2015
- Revised 10 April 2015
DOI:https://doi.org/10.1103/PhysRevC.91.054309
©2015 American Physical Society