muon capture

nuclear matrix

electron capture

double beta decay

scattering length

ca ca

double beta

neutral current

Physical Review Letters

We use coupled-cluster theory and nuclear interactions from chiral effective field theory to compute the nuclear matrix element for the neutrinoless double-$\ensuremath{\beta}$ decay of $^{48}\mathrm{Ca}$. Benchmarks with the no-core shell model in several light nuclei inform us about the accuracy of our approach. For $^{48}\mathrm{Ca}$ we find a relatively small matrix element. We also compute the nuclear matrix element for the two-neutrino double-$\ensuremath{\beta}$ decay of $^{48}\mathrm{Ca}$ with a quenching factor deduced from two-body currents in recent ab initio calculation of the Ikeda sum rule in $^{48}\mathrm{Ca}$ [Gysbers et al., Nat. Phys. 15, 428 (2019)].

Coupled-Cluster Calculations of Neutrinoless Double-β Decay in Ca48