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arXiv · 1210.2638

Neutron pair correlations in A=100 nuclei involved in neutrinoless double-$β$ decay

J. S. Thomas·S. J. Freeman·C. M. Deibel·T. Faestermann·R. Hertenberger·B. P. Kay·S. A. McAllister·A. J. Mitchell·J. P. Schiffer·D. K. Sharp·H. F. Wirth
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Abstract

The pairing properties of the neutrinoless double beta decay $(0\nu2β)$ candidate $^{100}$Mo have been studied, along with its daughter $^{100}$Ru, to provide input for nuclear matrix element calculations relevant to the decay. The $(p,t)$ two-neutron transfer reaction was measured on nuclei of $^{102,100}$Ru and $^{100,98}$Mo. The experiment was designed to have particular sensitivity to $0^{+}$ states up to excitation energies of $\sim 3$ MeV with high energy resolution. Measurements were made at two angles and L=0 transitions identified by the ratio of yields between the two angles. For the reactions leading to and from $^{100}$Ru, greater than 95% of the L=0 $(p,t)$ strength was in the ground state, but in $^{100}$Mo about 20% was in excited $0^{+}$ states. The measured $(p,t)$ data, together with existing $(t,p)$ data, suggest that $^{100}$Mo is a shape-transitional nucleus while $^{100}$Ru is closer to the spherical side of that transition. Theoretical calculations of the $0\nu2β$ nuclear matrix element may be complicated by this difference in shape.

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J. S. Thomas, S. J. Freeman, C. M. Deibel, T. Faestermann, R. Hertenberger, B. P. Kay, S. A. McAllister, A. J. Mitchell, J. P. Schiffer, D. K. Sharp, H. F. Wirth. 2012-10-09. Neutron pair correlations in A=100 nuclei involved in neutrinoless double-$β$ decay. https://doi.org/10.1103/physrevc.86.047304

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