Undergraduates
Why does the space shuttle returning to Earth cause two separate sonic booms?
Enriched Xenon Observatory (EXO)
Recent observations of tiny neutrino masses in solar, atmospheric, and reactor neutrino data raised several intriguing questions. Why are neutrinos so much lighter than the other particles? What is the absolute scale of the neutrino mass spectrum? And is the neutrino its own antiparticle, i.e. a Majorana particle? These questions are best addressed by searching for neutrinoless double beta decay, an exotic nuclear process which can shed light on both the absolute scale of the neutrino mass spectrum, and the underlying mechanism responsible for the tiny masses that we observe in nature.
The Enriched Xenon Observatory (EXO) is an experimental program designed to search for the neutrinoless double beta decay of Xe-136. The current phase of the experiment, EXO-200, uses 200 kg of liquid xenon with 80% enrichment. Double beta decay events are detected in an ultra-low background time projection chamber (TPC) by collecting both the scintillation light and the ionization charge. The detector began taking low background data since April, 2011. The collaboration made the first measurement of the two neutrino double decay of Xenon-136 and is actively working data analysis of the neutrinoless double beta decay. The next phase of the EXO experiment, denoted as full EXO, is a proposed 1-10 tons liquid or gas detector. We are working on several important R&D projects which can significantly improve the experimental sensitivity.
Research opportunities exist for both EXO-200 data analysis and R&D for full EXO.