Particle and Astroparticle Physics Seminar

The road towards reliable nuclear matrix elements for neutrinoless double beta decay

Antoine Belley

TRIUMF & UBC

The discovery of neutrioless double beta decay, a process in which two neutrons decay into two protons and two electrons without emitting any neutrinos, would have large implications on beyond the Standard Model physics. As experiments searching for the decay are in the planning phase of a next generation with hopes to completely probe the inverted mass hierarchy, the need for reliable nuclear matrix elements, which govern the rate of the decay, is stronger than ever. As a large discrepancy is found when computing this quantity with different nuclear models, a large unknown still exists on the sensitivity of these experiments to the effective neutrino mass. In this talk, I will present the challenges that arise when one tries to compute this quantity and most importantly to assess its uncertainty, as well as the recent efforts that have been made to overcome these challenges, with a special emphasis on results from the valence-space in medium similarity renormalization group (VS-IMSRG) ab initio method.