Speaker
Description
Reliable nuclear matrix elements play a crucial role in planning future neutrinoless double-beta-decay experiments, and in extracting the exciting new physics from them. Unfortunately, currently the nuclear matrix elements are not well constrained, and different many-body methods notably disagree on the values of them. Another open question is the possible need of quenching the axial-vector coupling constant – which enters the half-life expression of double-beta decay in fourth power.
In my talk, I will tackle these questions by discussing the impact of the recently acknowledged leading-order short-range term and hadronic two-body currents on the nuclear matrix elements of medium-heavy nuclei in pnQRPA framework. Furthermore, I will talk about complementary ways to constrain the nuclear matrix elements by using data on other nuclear observables. Specially, I will present our recent ab initio study on ordinary muon capture and discuss its potential to shed light on the need of quenching of the couplings at high-momentum-exchange regime relevant for neutrinoless double-beta decay.
