English

Large-scale shell-model analysis of the neutrinoless $\beta\beta$ decay of $^{48}$Ca

Nuclear Theory 2016-03-23 v1 High Energy Physics - Experiment High Energy Physics - Phenomenology Nuclear Experiment

Abstract

We present the nuclear matrix element for the neutrinoless double-beta decay of 48^{48}Ca based on large-scale shell-model calculations including two harmonic oscillator shells (sdsd and pfpf shells). The excitation spectra of 48^{48}Ca and 48^{48}Ti, and the two-neutrino double-beta decay of 48^{48}Ca are reproduced in good agreement to experiment. We find that the neutrinoless double-beta decay nuclear matrix element is enhanced by about 30\% compared to pfpf-shell calculations. This reduces the decay lifetime by almost a factor of two. The matrix-element increase is mostly due to pairing correlations associated with cross-shell sdsd-pfpf excitations. We also investigate possible implications for heavier neutrinoless double-beta decay candidates.

Keywords

Cite

@article{arxiv.1602.07822,
  title  = {Large-scale shell-model analysis of the neutrinoless $\beta\beta$ decay of $^{48}$Ca},
  author = {Y. Iwata and N. Shimizu and T. Otsuka and Y. Utsuno and J. Menendez and M. Honma and T. Abe},
  journal= {arXiv preprint arXiv:1602.07822},
  year   = {2016}
}

Comments

Phys. Rev. Lett., accepted