Krishna S. Kumar



Jason Bane 

Devin Cesmecioglu

Alexandria Nolan


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nEXO Experiment


EXO-200 Experiment




Search for Neutrinoless Double Beta Decay

The Enriched Xenon Observatory (EXO) aims to detect "neutrino-less double-beta decay" using large amounts of xenon isotopically enriched in the isotope 136. Simply stated the long-term goals of the project are:

Probe the Majorana nature of neutrinos

Access effective Majorana masses approaching 10 meV

The EXO-200 experiment used 200 kg of Xenon enriched to 80% in the isotope 136. It ran from 2010 to 2018 at the Waste Isolation Pilot Plant (WIPP) in Carlsbad, NM.

nEXO is a 5 tonne, 90%-enriched liquid xenon time projection chamber being designed to be sensitive to neutrinoless double-beta decay half-lives approaching 1028 years. 

Beyond nEXO, there are plans to identify the final state of the decay, a barium atom, using high resolution, single atom spectroscopy.

The first observation of the 2-neutrino double-beta decay in 136Xe was published in PRL in 2011: arXiv:1108.4193

The final results of the EXO-200 experiment was published in PRL in 2019: arXiv:1906.02723