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

The double-beta-decay Q values of Te-130, Te-128, and Te-120 have been determined from parent-daughter mass differences measured with the Canadian Penning Trap mass spectrometer. The Xe-132-Xe-129 mass difference, which is precisely known, was also determined to confirm the accuracy of these results. The Te-130 Q value was found to be 2527.01 +/- 0.32 keV, which is 3.3 keV lower than the 2003 Atomic Mass Evaluation recommended value and is consistent with another recent Penning trap measurement. The Te-128 and Te-120 Q values were found to be 865.87 +/- 1.31 and 1714.81 +/- 1.25 keV, respectively. For Te-120, 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 beta(+) emission.