Neutrinoless <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>β</mml:mi><mml:mi>β</mml:mi></mml:mrow></mml:math>-decay nuclear matrix elements from two-neutrino <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>β</mml:mi><mml:mi>β</mml:mi></mml:mrow></mml:math>-decay data
Lotta Jokiniemi, B. Romeo, Pablo Soriano, J. Menéndez
Abstract
We study two-neutrino ($2\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$) and neutrinoless double-$\ensuremath{\beta}$ ($0\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$) decays in the nuclear shell model and proton-neutron quasiparticle random-phase approximation (pnQRPA) frameworks. Calculating the decay half-life of several dozens of nuclei ranging from calcium to xenon with the shell model, and of $\ensuremath{\beta}\ensuremath{\beta}$ emitters with a wide range of proton-neutron pairing strengths in the pnQRPA, we observe good linear correlations between $2\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$- and $0\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$-decay nuclear matrix elements for both methods. We then combine the correlations with measured $2\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$-decay half-lives to predict $0\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$-decay matrix elements with theoretical uncertainties based on our systematic calculations. Our results include two-body currents and the short-range $0\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$-decay operator.