Double-beta decay Q values of 130Te, 128Te, and 120Te

TL;DR

This paper precisely measures the double-beta decay Q values of isotopes 130Te, 128Te, and 120Te using Penning Trap mass spectrometry, reducing uncertainties and enabling improved experimental searches for neutrinoless double-beta decay.

Contribution

The study provides highly accurate Q values for three tellurium isotopes, significantly reducing uncertainties and confirming previous measurements, which enhances the potential for future neutrinoless double-beta decay experiments.

Findings

130Te Q value is 2527.01(32) keV, 3.3 keV lower than previous recommended value.

Uncertainty for 128Te and 120Te Q values reduced by nearly a factor of 8.

Results enable more sensitive searches for neutrinoless double-electron capture.

Abstract

The double-beta decay Q values of 130Te, 128Te, and 120Te have been determined from parent-daughter mass differences measured with the Canadian Penning Trap mass spectrometer. The 132Xe-129Xe mass difference, which is precisely known, was also determined to confirm the accuracy of these results. The 130Te Q value was found to be 2527.01(32) keV which is 3.3 keV lower than the 2003 Atomic Mass Evaluation recommended value, but in agreement with the most precise previous measurement. The uncertainty has been reduced by a factor of 6 and is now significantly smaller than the resolution achieved or foreseen in experimental searches for neutrinoless double-beta decay. The 128Te and 120Te Q values were found to be 865.87(131) keV and 1714.81(125) keV, respectively. For 120Te, this reduction in uncertainty of nearly a factor of 8 opens up the possibility of using this isotope for sensitive searches for neutrinoless double-electron capture and electron capture with positron emission.