Ab Initio Short-Range Nuclear Matrix Elements for Neutrinoless Double-Beta Decay.

We present converged ab initio calculations of short-range neutrinoless double-beta (0νββ)-decay nuclear matrix elements for the key experimental isotopes ^{76}Ge, ^{82}Se, ^{130}Te, and ^{136}Xe. Starting from different nuclear forces derived from chiral effective field theory, we apply the in-medium similarity renormalization group to obtain an effective valence-space Hamiltonian along with consistently transformed 0νββ-decay operators. We then obtain a range of values for the matrix elements that is consistent with, but generally smaller than, those from phenomenology. Finally, we combine our results with current limits from 0νββ-decay searches to obtain constraints for the sterile-neutrino mixing-mass parameter space when considering the inclusion of a fourth, sterile neutrino.