New determination of double-β-decay properties in48Ca: High-precisionQββ-value measurement and improved nuclear matrix element calculations

Autor: Aaron Gallant, M. R. Pearson, U. Chowdhury, A. Grossheim, T.D. Macdonald, B.E. Schultz, M.C. Simon, T. Brunner, Mihai Horoi, Jens Dilling, Roman Senkov, Jonathan Engel, Vanessa V. Simon, A.A. Kwiatkowski, Jason D. Holt, A. Chaudhuri, Kai Zuber, M. Eibach, A. Lennarz
Rok vydání: 2014
Předmět:
Zdroj: Physical Review C. 89
ISSN: 1089-490X
0556-2813
DOI: 10.1103/physrevc.89.045502
Popis: We report a direct measurement of the Q-value of the neutrinoless double-beta-decay candidate 48Ca at the TITAN Penning-trap mass spectrometer, with the result that Q = 4267.98(32) keV. We measured the masses of both the mother and daughter nuclides, and in the latter case found a 1 keV deviation from the literature value. In addition to the Q-value, we also present results of a new calculation of the neutrinoless double-beta-decay nuclear matrix element of 48Ca. Using diagrammatic many-body perturbation theory to second order to account for physics outside the valence space, we constructed an effective shell-model double-beta-decay operator, which increased the nuclear matrix element by about 75% compared with that produced by the bare operator. The new Q-value and matrix element strengthen the case for a 48Ca double-beta-decay experiment.
Databáze: OpenAIRE