We presented a novel no-core configuration-interaction approach,
which is based on mixing the isospin- and
angular-momentum-projected deformed DFT configurations. The model is
specifically tailored to determining the low-lying spectra and
-decay transitions in
nuclei, where the isospin degree of
freedom is essential. The model can be viewed as a variant of
the no-core shell model. Its advantage over the standard
shell model formulation is that it can be applied, at least in principle, to
any nucleus of arbitrary mass and number parity.
Two applications of the model, both relevant to studies of
superallowed Fermi decays, were presented. The model has been
used to compute the
spectrum of
Zn and ISB corrections
to the Fermi
decays between the
and
isobaric analogue states in
Ca and
K. We demonstrated that without adjusting any single
parameter, it well reproduces the spectra of
states.
Predictions for the ISB corrections appear to be, at least at
present, somewhat less reliable. The reason is that the isospin
mixing is a very subtle effect, requiring a perfect matching of
spaces of states used in the parent and daughter nuclei, which is
difficult to achieve in practice. Work toward improving this aspect
of the model is in progress.
This work was supported in part by the Polish National Science Centre (NCN) under Contract No. 2012/07/B/ST2/03907, by the THEXO JRA within the EU-FP7-IA project ENSAR (No. 262010), by the ERANET-NuPNET grant SARFEN of the Polish National Centre for Research and Development (NCBiR), and by the Academy of Finland and University of Jyväskylä within the FIDIPRO programme.
Jacek Dobaczewski 2014-12-06