Unveiling the mysteries of neutrinoless double beta decay: exploring Nuclear Matrix Elements and their impact on Majorana mass sensitivities

Parallel Talk presented at the XX International Workshop on Neutrino Telescopes - Venice 23-27 October 2023 

Abstract:

Nuclear Matrix Elements (NME) are a crucial input for the interpretation of neutrinoless double beta decay data. A representative set of recent NME calculations from different methods is taken, and a combined analysis of the available data performed in order to investigate the impact on the future sensitivity on the effective Majorana mass. A crucial role is played by the recently discovered short-range contribution to the NME, induced by light Majorana neutrino masses. Depending on the NME model and the relative sign of the long- and short-range contributions, the current bounds change, and the sensitivity of next-generation experiments can be either pushed beyond the inverted mass ordering region or never reach this one. Furthermore, perspectives on the possibility to distinguish between different NME calculations by assuming a positive signal and by combining measurements from different isotopes is presented.

This project has received funding and support from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 860881-HIDDeN