Uncertainties in nuclear transition matrix elements for β+β+ and εβ+ modes of neutrinoless positron double-β decay within the projected Hartree-Fock-Bogoliubov model

Abstract

Uncertainties in the nuclear transition matrix elements M(0ν) and M(0N) of the double-positron emission (β+β +)0ν and electron-positron conversion (εβ+)0ν modes owing to the exchange of light and heavy Majorana neutrinos, respectively, are calculated for 96Ru, 102Pd, 106Cd, 124Xe, 130Ba, and 156Dy isotopes by employing the PHFB model with four different parametrizations of the pairing plus multipolar two-body interactions and three different parametrizations of the Jastrow short-range correlations. In all cases but for 130Ba the uncertainties are smaller than 14% for light Majorana neutrino exchange and 35% for the exchange of a heavy Majorana neutrino.