Measurement of the 136Xe two-neutrino double-β-decay half-life via direct background subtraction in NEXT

We report a measurement of the half-life of the Xe-136 two-neutrino double-beta decay performed with a novel direct-background-subtraction technique. The analysis relies on the data collected with the NEXT-White detector operated with Xe-136-enriched and Xe-136-depleted xenon, as well as on the topology of double-electron tracks. With a fiducial mass of only 3.5 kg of Xe, a half-life of 2.34(-0.46)(+0.80) (stat)(-0.17)(+0.30) (sys) x 10(21) yr is derived from the background-subtracted energy spectrum. The presented technique demonstrates the feasibility of unique background-model-independent neutrinoless double-beta-decay searches.

Automated summary

We report a measurement of the half-life of the Xe-136 two-neutrino double-beta decay using a novel direct-background-subtraction technique. The analysis is based on data collected with the NEXT-White detector and the topology of double-electron tracks. The presented technique demonstrates the feasibility of background-model-independent neutrinoless double-beta-decay searches.