The atomic masses of Ge74, Se74, Ge76, and Se76 have been determined from cyclotron frequency ratios of pairs of ions simultaneously trapped in a cryogenic Penning trap. Allowing for cancellation of systematic errors in the mass differences between isobars, we determine the Q value for double-electron capture of Se74 to be 1209.240(7) keV, and the Q value for double-electron emission of Ge76 to be 2039.061(7) keV. The new Q2EC value for Se74 precludes a large resonant enhancement for neutrinoless double-electron capture.
|Journal||Physical Review C - Nuclear Physics|
|State||Published - Mar 23 2010|