Projected sensitivity of the LUX-ZEPLIN experiment to the $0\nu\beta\beta$ decay of $^{136}$Xe

Understand

The LUX-ZEPLIN (LZ) experiment will enable a neutrinoless double beta decay search in parallel to the main science goal of discovering dark matter particle interactions.

• We report the expected LZ sensitivity to $^{136}$Xe neutrinoless double beta decay, taking advantage of the significant ($>$600 kg) $^{136}$Xe mass contained within the active volume of LZ without isotopic enrichment.
• After 1000 live-days, the median exclusion sensitivity to the half-life of $^{136}$Xe is projected to be 1.06$\times$10$^{26}$ years (90% confidence level), similar to existing constraints.
• We also report the expected sensitivity of a possible subsequent dedicated exposure using 90% enrichment with $^{136}$Xe at 1.06$\times$10$^{27}$ years.