Speaker: Vincenzo Cirigliano T-2: NUC & PARTICLE PHYS, ASTROPHYS & COSMOL LANL “Searching for new physics with single and double beta decay” Abstract: Low-energy precision measurements provide unique probes of new physics beyond the so-called Standard Model of electroweak and strong interactions. After a general introduction on new physics searches at the precision frontier, I will focus on precision beta decay measurements and searches for neutrinoless double beta decay, two probes in which LANL has world-leading capabilities. I will first discuss how ongoing beta decay measurements have the potential to unveil new interactions that are up to ten thousand times weaker than the known weak force, mediated by hypothetical super-heavy particles with mass up to 10,000 times the proton masses. In the second part of the talk I will discuss neutrinoless double beta decay as a probe of lepton number non-conservation, and its implications for the Majorana nature of neutrinos and the generation of the matter-antimatter asymmetry in the universe. Throughout, I will highlight the theoretical challenges and progress associated with the interpretation of these sensitive experiments.