Efficient calculation of chiral three-nucleon forces up to N3LO for ab initio studies

Understand

We present a novel framework to decompose three-nucleon forces in a momentum space partial-wave basis.

• The new approach is computationally much more efficient than previous methods and opens the way to ab initio studies of few-nucleon scattering processes, nuclei and nuclear matter based on higher-order chiral 3N forces.
• We use the new framework to calculate matrix elements of chiral three-nucleon forces at N2LO and N3LO in large basis spaces and carry out benchmark calculations for neutron matter and symmetric nuclear matter.
• We also study the size of the individual three-nucleon force contributions for $^3$H.