Uncertainties in nuclear transition matrix elements for ${\beta }^{+}{\beta }^{+}$ and $\epsilon {\beta }^{+}$ modes of neutrinoless positron double-$\beta$ decay within PHFB model

P. K. Rath, R. Chandra, K. Chaturvedi +3

Uncertainties in the nuclear transition matrix elements $M^{(0\nu )}$ and $M^{(0N)}$ of the double-positron emission $({\beta }^{+}{\beta }^{+}{)}_{0\nu }$ and electron-positron conversion $(\varepsilon…