Demonstration of Single-Barium-Ion Sensitivity for Neutrinoless Double-Beta Decay Using Single-Molecule Fluorescence...

Area of Science:

• Nuclear Physics
• Particle Physics
• Quantum Optics

Background:

• Neutrinoless double-beta decay (0νββ) searches are crucial for understanding neutrino properties and matter-antimatter asymmetry.
• ^{136}Xe is a promising candidate for 0νββ decay studies, but identifying the barium daughter nucleus is challenging.
• Existing detection methods face limitations in sensitivity and background noise.

Purpose of the Study:

• To develop a novel method for tagging the barium daughter nucleus produced in the double-beta decay of ^{136}Xe.
• To demonstrate the capability of single molecule fluorescent imaging (SMFI) for detecting individual barium ions with high precision.
• To lay the groundwork for a new generation of background-free 0νββ decay experiments.

Main Methods:

• Utilized single molecule fluorescent imaging (SMFI) to achieve individual barium dication (Ba^{++}) resolution.
• Employed a transparent scanning surface for ion detection.
• Verified single ion detection through single-step photobleaching.
• Achieved superresolution localization (∼2 nm) and high statistical significance (12.9σ) for ion detection.

Main Results:

• Demonstrated the successful detection of individual Ba^{++} ions using SMFI.
• Confirmed the single ion nature of the detected events.
• Achieved precise spatial localization of individual ions.
• Established a high signal-to-background ratio for ion detection.

Conclusions:

• The developed SMFI technique provides a robust method for tagging barium daughters from ^{136}Xe decay.
• This approach paves the way for background-free neutrinoless double-beta decay searches.
• Coupling SMFI with high-pressure xenon gas time projection chambers holds significant promise for future 0νββ experiments.