New experimental limits on the alpha decays of lead isotopes

TL;DR

This study used a novel Roman lead-based cryogenic detector to set new, more stringent experimental limits on the alpha decays of lead isotopes, including 204Pb, enhancing understanding of nuclear stability.

Contribution

First use of ancient Roman lead in a cryogenic detector to improve limits on lead isotope alpha decays, demonstrating advanced discrimination capabilities.

Findings

Established a new limit of T_{1/2} > 1.4×10^{20} years for 204Pb alpha decay

Demonstrated effective discrimination between alpha and beta/gamma interactions at low energies

Introduced a novel detector setup using Roman lead for rare decay searches.

Abstract

For the first time a PbWO4 crystal was grown using ancient Roman lead and it was run as a cryogenic detector. Thanks to the simultaneous and independent read-out of heat and scintillation light, the detector was able to discriminate beta/gamma interactions with respect to alpha particles down to low energies. New more stringent limits on the alpha decays of the lead isotopes are presented. In particular a limit of T_{1/2} > 1.4*10^20 y at a 90% C.L. was evaluated for the alpha decay of 204Pb to 200Hg.