Ubirajara Van Kolck, "Neutrinoless Double-Beta Decay in Nuclear Effective Field Theory"

Wednesday 27 Nov 2024, 14:30 → 15:30 Europe/Rome

0M02

The single dimension-five operator in the Standard Model (SM) Effective Field Theory (EFT), which might be expected to provide the largest deviation from the SM, gives rise to both neutrino masses and lepton-number violation. Non-zero neutrino masses have been measured and a worldwide experimental search is underway for the main signal of lepton-number violation, the neutrinoless double-beta decay (NDBD) of heavy nuclei. The model-independent description of the basic process, where two neutrons mutate into two protons and two electrons, is given by nuclear EFTs constructed consistently with SMEFT. I show that at leading order the standard light Majorana neutrino exchange needs to be supplemented by a short-range mechanism with a currently unknown coefficient.Calculations of NDBD matrix elements confirm the importance of this new mechanism when an estimate is made for its coefficient from known two-nucleon charge-independence breaking using chiral symmetry. I end with a discussion of other possible ways to determine this coefficient.

 

Biography: Prof. Ubirajara van Kolck is currently director of the European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*) in Trento, Directeur de Recherche de Classe Exceptionnelle at CNRS-Orsay (FRA), and Professor at Department of Physics of the University of Arizona (USA). He has been awarded of several scientific prizes, among them “2020 Herman Feshbach Prize in Theoretical Nuclear Physics” from the American Physical Society, and Prix Paul Langevin 2015” from the Société Française de Physique. He is a worldwide known expert on the development of Effective Field Theories (EFTs), in particular of their applications to problems at the interface between particle and nuclear physics, and to problems in molecular physics.