Challenges in double charge exchange measurements for neutrino physics

Abstract

The neutrinoless double beta (0νββ) decay, if observed, has important implications on particle physics, cosmology and fundamental physics. In particular it can give access to the effective neutrino mass. In order to extract such information from the 0νββ-decay half-life measurement, the knowledge of the Nuclear Matrix Elements (NME) is of utmost importance. In this context the NUMEN and the NURE projects aim to extract information on the NME by measuring the Double Charge Exchange (DCE) reaction cross section in selected systems of interest for the 0νββ-decay. The experimental difficulties that have to be faced are the measurements at very forward-angle, the very low cross section of the process to be measured, the requirement of a high energy resolution and, eventually, the unambiguous identification of the DCE reaction from other competing processes. The large-acceptance spectrometer MAGNEX, present at INFN-LNS, Catania fulfills all the requirement above mentioned.