The NUMEN Project: An Update of the Facility Toward the Future Experimental Campaigns

Abstract

The goal of NUMEN project is to access experimentally driven information on Nuclear Matrix Elements (NME) involved in the neutrinoless double beta decay (0νββ) by accurate measurements of the cross sections of heavy-ion induced double charge-exchange reactions. In particular, the (18O, 18Ne) and (20Ne, 20O) reactions are adopted as tools for β+β+ and β−β− decays, respectively. The experiments are performed at INFN–Laboratory Nazionali del Sud (LNS) in Catania using the Superconducting Cyclotron to accelerate the beams and the MAGNEX magnetic spectrometer to detect the reaction products. The measured cross sections are very low, limiting the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. In order to make feasible a systematic study of all the candidate nuclei, a major upgrade of the LNS facility is foreseen to increase the experimental yield by more than two orders of magnitude. To this purpose, frontier technologies are being developed for both the accelerator and the detection systems. An update description of the NUMEN project is presented here, focusing on recent achievements from the R&D activity.

Double charge-exchange reactions for the nuclear matrix elements of neutrinoless double beta decay

“…This measurement provides, for the first time, the estimation of the order of magnitude of the extremely low DCE cross section for the transition under study. The upgrade of the INFN-LNS superconducting cyclotron and of the MAGNEX FPD is now in progress [4,17,18,19], giving the opportunity for a future deeper exploration of this reaction with a much higher beam current and consequently with better statistics. A parallel activity searching for the most promising probes for double charge exchange reactions has been carried out in the recent years at RCNP and RIKEN laboratories in Japan.…”

“…The NUMEN (NUclear Matrix Elements for Neutrinoless double beta decay) project [1,2,3,4] proposes to use heavy-ion induced Double Charge Exchange reactions (HI-DCE) as a tool to access quantitative information, relevant for 0νββ decay nuclear matrix elements (NME). A critical aspect of 0νββ is that the associated NME must be known with high accuracy to obtain information on the term beyond-standard-model, connected with the neutrino absolute mass.…”

Recent experimental activity on heavy-ion induced reactions within the NUMEN project

“…2. A dedicated run was also performed on 12 C target, in order to compare reaction models with an easier light system. The reduction and analysis of the collected data from these campaigns is presently in progress.…”

LTCC Strip Electrode Arrays for Gas Electron Multiplier Detectors

“…In this work, we focus on the development of the sensing electrode array in the LTCC technology. Such a complete device could be a breakthrough not only in space missions but also in nuclear physics research, such as the NUMEN project, which requires fine resolution but also radiation hardness, to withstand the high rate of impinging particles [16,17].…”