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arXiv · 1304.0434

Role of three-nucleon forces and many-body processes in nuclear pairing

J. D. Holt·J. Menendez·A. Schwenk
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Abstract

We present microscopic valence-shell calculations of pairing gaps in the calcium isotopes, focusing on the role of three-nucleon (3N) forces and many-body processes. In most cases, we find a reduction in pairing strength when the leading chiral 3N forces are included, compared to results with low-momentum two-nucleon (NN) interactions only. This is in agreement with a recent energy density functional study. At the NN level, calculations that include particle-particle and hole-hole ladder contributions lead to smaller pairing gaps compared with experiment. When particle-hole contributions as well as the normal-ordered one- and two-body parts of 3N forces are consistently included to third order, we find reasonable agreement with experimental three-point mass differences. This highlights the important role of 3N forces and many-body processes for pairing in nuclei. Finally, we relate pairing gaps to the evolution of nuclear structure in neutron-rich calcium isotopes and study the predictions for the 2+ excitation energies, in particular for 54Ca.

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J. D. Holt, J. Menendez, A. Schwenk. 2013-06-11. Role of three-nucleon forces and many-body processes in nuclear pairing. https://doi.org/10.1088/0954-3899%2F40%2F7%2F075105

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