Q value of the superallowed decay of Mg22 and the calibration of the Na21(p,γ) experiment

Abstract

The masses of the radioactive nuclei and have been measured with the Canadian Penning trap on-line mass spectrometer to a precision of and , respectively. A value of for the superallowed decay of is obtained from the difference of these two masses. With this precise value, the value for this decay is determined with improved precision and is found to be consistent with the existing precision data set of superallowed Fermi emitters. This provides an important test of the isospin symmetry-breaking corrections. If the mass of determined here is used in the calibration of a recent measurement, part of the discrepancy observed in that measurement is removed.