Search for 136Xe neutrinoless double beta decay with the Enriched Xenon Observatory (EXO)

The EXO collaboration is searching for the neutrinoless double beta decay of 136Xe. Such observation would determine an absolute mass scale for the neutrinos, establish their Majorana nature, and uncover physics beyond the Standard Model. The EXO-200 detector is a single phase liquid xenon ultra low background TPC (Time Projection Chamber), with an active mass of 110 kg of 80.6% enriched xenon in the isotope 136. The detector is currently operating at the WIPP site and has been collecting data with enriched xenon since May 2011. The data collected give a lower limit for the neutrinoless double beta decay half-life of 136Xe: T > 1.6*1025 years at 90% C.L. The same data give a lower limit for the 2 neutrinos double beta decay of 136Xe: T > 2.23*1021 years that agrees with experimental values found in the literature