Transfer reactions between odd-odd and even-even nuclei by using IBFFM

Abstract

Spectroscopic Amplitudes (SA) in the Interacting Boson Fermion Fermion Model (IBFFM) are necessary for the computation of 0νββ decays but also for cross sections of heavy-ion reactions, in particular, Double Charge Exchange reactions for the NUMEN collaboration, if one does not want to use the closure limit. We present for the first time: i) the formalism and operators to compute in a general case the spectroscopic amplitudes in the scheme IBFFM from an even-even to odd-odd nuclei, in a way suited to be used in reaction code, i.e., extracting the contribution of each orbital; 2) the odd-odd nuclei as described by the old IBFFM are obtained for the first time with the new implementation of Machine Learning (ML) techniques for fitting the parameters, getting a more realistic description. The one body transition densities for 116 Cd → 116 In and 116 In → 116 Sn are part of the experimental program of the NUMEN experiment, which aims to find constraints on Neutrinoless double beta decay matrix elements.