Determination of the direct double-beta-decay Q value of Zr-96 and atomic masses of Zr-90-92,Zr-94,Zr-96 and Mo-92,Mo-94-98,Mo-100

作者：Gulyuz K^*; Ariche J; Bollen G; Bustabad S; Eibach M; Izzo C; Novario S J; Redshaw M; Ringle R; Sandler R; Schwarz S; Valverde A A

来源：Physical Review C, 2015, 91(5): 055501.

DOI：10.1103/PhysRevC.91.055501

Experimental searches for neutrinoless double-beta decay offer one of the best opportunities to look for physics beyond the standard model. Detecting this decay would confirm the Majorana nature of the neutrino, and a measurement of its half-life can be used to determine the absolute neutrino mass scale. Important to both tasks is an accurate knowledge of the Q value of the double-beta decay. The LEBIT Penning trap mass spectrometer was used for the first direct experimental determination of the Zr-96 double-beta decay Q value: Q(beta beta) = 3355.85(15) keV. This value is nearly 7 keV larger than the 2012 Atomic Mass Evaluation [M. Wang et al., Chin. Phys. C 36, 1603 (2012)] value and one order of magnitude more precise. The 3-sigma shift is primarily due to a more accurate measurement of the Zr-96 atomic mass: m(Zr-96) = 95.908 277 35(17) u. Using the new Q value, the 2 nu beta beta-decay matrix element, vertical bar M-2 nu vertical bar, is calculated. Improved determinations of the atomic masses of all other zirconium (Zr-90-92,Zr-94,Zr-96) and molybdenum (Mo-92,Mo-94-98,Mo-100) isotopes using both C-12(8) and Rb-87 as references are also reported.

• 出版日期2015-5-6