An optimized chiral nucleon-nucleon interaction at next-to-next-to-leading order

Understand

We optimize the nucleon-nucleon interaction from chiral effective field theory at next-to-next- to-leading order.

• The resulting new chiral force NNLOopt yields \chi^2 \approx 1 per degree of freedom for laboratory energies below approximately 125 MeV.
• In the A = 3, 4 nucleon systems, the contributions of three-nucleon forces are smaller than for previous parametrizations of chiral interactions.
• We use NNLOopt to study properties of key nuclei and neutron matter, and demonstrate that many aspects of nuclear structure can be understood in terms of this nucleon-nucleon interaction, without explicitly invoking three-nucleon forces.