Talk title: In search of Majorana neutrinos and micron-scale interactions
Abstract: While the Standard Model (SM) has been exceptionally successful in describing nature at a fundamental level, there remain key questions that it cannot address. The discovery of nonzero neutrino masses provides direct evidence of physics beyond the minimal SM, yet the mechanism by which these masses are generated remains unknown. In addition, the SM does not include gravity—a force well understood over macroscopic distances but largely unexplored at short length scales. In this talk, I will describe experimental efforts to address both of these questions. nEXO is a planned search for neutrinoless double-beta decay, a process that, if observed, would establish neutrinos as Majorana fermions and provide insight into the mass generation mechanism. The nEXO detector will be a time projection chamber containing five tonnes of liquid xenon enriched to 90% in xenon-136. I will describe the development of a light response calibration scheme and a low-radioactivity xenon purifier for nEXO. Following this, I will outline my work on a tabletop experiment that uses optically levitated microspheres as precision force sensors to search for modifications to gravity at short distances. I will present the latest constraints on micron-scale Yukawa interactions and a systematic study of the backgrounds limiting the search.
Host: David Moore