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Iwata Y, Shimizu N, Otsuka T, Utsuno Y, Menéndez J, Honma M, Abe T. Large-Scale Shell-Model Analysis of the Neutrinoless ββ Decay of ^{48}Ca. PHYSICAL REVIEW LETTERS 2016; 116:112502. [PMID: 27035297 DOI: 10.1103/physrevlett.116.112502] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Indexed: 06/05/2023]
Abstract
We present the nuclear matrix element for the neutrinoless double-beta decay of ^{48}Ca based on large-scale shell-model calculations including two harmonic oscillator shells (sd and pf shells). The excitation spectra of ^{48}Ca and ^{48}Ti, and the two-neutrino double-beta decay of ^{48}Ca are reproduced in good agreement to the experimental data. We find that the neutrinoless double-beta decay nuclear matrix element is enhanced by about 30% compared to pf-shell calculations. This reduces the decay lifetime by almost a factor of 2. The matrix-element increase is mostly due to pairing correlations associated with cross-shell sd-pf excitations. We also investigate possible implications for heavier neutrinoless double-beta decay candidates.
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Affiliation(s)
- Y Iwata
- Center for Nuclear Study, The University of Tokyo, 113-0033 Tokyo, Japan
| | - N Shimizu
- Center for Nuclear Study, The University of Tokyo, 113-0033 Tokyo, Japan
| | - T Otsuka
- Center for Nuclear Study, The University of Tokyo, 113-0033 Tokyo, Japan
- Department of Physics, The University of Tokyo, 113-0033 Tokyo, Japan
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Instituut voor Kern- en Stralingsfysica, Katholieke Universiteit Leuven, B-3001 Leuven, Belgium
| | - Y Utsuno
- Center for Nuclear Study, The University of Tokyo, 113-0033 Tokyo, Japan
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, 319-1195 Ibaraki, Japan
| | - J Menéndez
- Department of Physics, The University of Tokyo, 113-0033 Tokyo, Japan
| | - M Honma
- Center for Mathematical Sciences, University of Aizu, 965-8580 Fukushima, Japan
| | - T Abe
- Department of Physics, The University of Tokyo, 113-0033 Tokyo, Japan
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