Determination of theG76eDouble Beta DecayQValue

Abstract

The Q value of the (76)Ge double beta decay has been determined by measuring the masses of (76)Ge and (76)Se in a Penning trap using neon- and fluorinelike ions. The obtained masses are 75.921 402 758(96) u and 75.919 213 795(81) u, respectively. The systematic errors of these two determinations are nearly equal, and therefore, the remaining systematic uncertainty of the Q value is drastically reduced. A Q value of 2 039.006(50) keV was obtained improving the accuracy of the accepted value by a factor of 6.

Status of Evidence for Neutrinoless Double Beta Decay, and the Future: Genius and Genius-Tf

“…This is compatible with the Q-value [77,78] of the double beta decay process. We emphasize, that at this energy no γ-line is expected according to the compilations in [79] (see discussion in section 2).…”

“…The Q value for neutrinoless double beta decay has been determined recently with very high precision to be Q ββ =2039.006(50) keV [77,78].…”

Nuclear matrix elements for neutrinoless double-beta decay and double-electron capture

“…For a long time there was no way to identify promising isotopes for experimental search of 0νECEC, because of poor experimental accuracy of measurement of Q-values of the order of 1 -10 keV for medium heavy nuclei. Progress in precision measurement of atomic masses with Penning traps [57][58][59] has revived the interest in the old idea on the resonance 0νECEC. The accuracy of Q-values at around 100 eV was achieved.…”

Search for 0νββ-decay with gerda phase II

“…For the Coax detectors the resolution during data taking is slightly worse, most likely due to sligtly higher long term gain shifts. The interpolated resolution at the Q-value of 76 Ge at 2039 keV [11] is (3.0±0.2) keV and (4.0±0.2) keV for the BEGe and Coax detectors, respectiveley. For the latter the difference between the resolution obtained in calibration data and background data has been added linearly.…”