Double -β Decay Q values of Te130, Te128, and Te120

The double-β-decay Q values of Te130, Te128, and Te120 have been determined from parent-daughter mass differences measured with the Canadian Penning Trap mass spectrometer. The Xe132-Xe129 mass difference, which is precisely known, was also determined to confirm the accuracy of these results. The Te130 Q value was found to be 2527.01A±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 Te128 and Te120 Q values were found to be 865.87A±1.31 and 1714.81A±1.25 keV, respectively. For Te120, 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 β+ emission. © 2009 The American Physical Society