PHYSICS PHD DISSERTATION DEFENSE: Michael Jewell

Ph.D. Candidate:  Michael Jewell

Research Advisor:  Giorgio Gratta

Date: Monday, March 30th, 2020
Time: 9AM
Location:  Via Zoom https://stanford.zoom.us/j/355759518

Title: Search for Neutrinoless Double Beta Decay with EXO-200 and nEXO

Abstract:  Neutrinoless Double Beta Decay is a theorized nuclear decay in which a nucleus decays via the emission of two electrons but no neutrinos.  Detection of this lepton number violating process represents the best test of the Majorana nature of neutrinos, which could potentially provide an elegant mechanism by which neutrinos obtain mass.  Both the recently decommissioned EXO-200 and the future experiment nEXO search for this hypothesized decay using liquid xenon time projection chambers filled with xenon enriched in the isotope \isotope{Xe}{136}.  In the first part of this talk, the results from the final neutrinoless double beta decay search of EXO-200 with the complete dataset is presented.  This includes a description of the advanced analysis techniques used to maximize the topological discrimination between double beta signal and gamma backgrounds.  The second part of this talk presents the current state of R\&D efforts towards designing the planned tonne scale experiment, with focus on the characterization of charge-detecting tiles which are proposed to make up the anode plane of nEXO.