Searching for Neutrinoless Double-Beta Decay of $^{136}$Xe with PandaX-4T

TL;DR

This paper reports a search for neutrinoless double-beta decay of $^{136}$Xe using the PandaX-4T detector, setting the most stringent limit to date with no observed signal.

Contribution

First search for neutrinoless double-beta decay of $^{136}$Xe with PandaX-4T, establishing a new lower half-life limit using natural xenon.

Findings

No significant excess observed over background

Lower limit on half-life set at 2.1 x 10^{24} years

Most stringent constraint from a natural xenon detector to date

Abstract

We report the search for neutrinoless double-beta decay of $^{136}$Xe from the PandaX-4T experiment with a 3.7-tonne natural xenon target. The data reconstruction and the background modeling are optimized in the MeV energy region. A blind analysis is performed with data from the commissioning run and the first science run. No significant excess of signal over the background is observed. A lower limit on the half-life of $^{136}$Xe neutrinoless double-beta decay is established to be $2.1 \times 10^{24}$~yr at the 90\% confidence level, with a $^{136}$Xe exposure of 44.6~kg$\cdot$year. Our result represents the most stringent constraint from a natural xenon detector to date.