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arXiv · 2109.13303

The importance of few-nucleon forces in chiral effective field theory

C. -J. Yang·A. Ekström·C. Forssén·G. Hagen·G. Rupak·U. van Kolck
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Abstract

We study the importance of few-nucleon forces in chiral effective field theory for describing many-nucleon systems. A combinatorial argument suggests that three-nucleon forces -- which are conventionally regarded as next-to-next-to-leading order -- should accompany the two-nucleon force already at leading order (LO) starting with mass number $A\approx 10-20$. We find that this promotion enables the first realistic description of the $^{16}$O ground state based on a renormalization-group-invariant LO interaction. We also performed coupled-cluster calculations of the equation of state for symmetric nuclear matter and our results indicate that LO four-nucleon forces could play a crucial role for describing heavy-mass nuclei. The enhancement mechanism we found is very general and could be important also in other many-body problems.

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C. -J. Yang, A. Ekström, C. Forssén, G. Hagen, G. Rupak, U. van Kolck. 2021-09-27. The importance of few-nucleon forces in chiral effective field theory. https://arxiv.org/abs/2109.13303

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