Neutron matter at next-to-next-to-next-to-leading order in chiral effective field theory

TL;DR

This paper presents the first complete N3LO calculation of neutron matter energy in chiral EFT, including 3N and 4N forces, providing valuable constraints for astrophysical neutron-rich matter.

Contribution

It introduces the first full N3LO neutron matter calculation with subleading 3N and leading 4N forces, advancing the precision of theoretical predictions.

Findings

Large contributions from N3LO 3N forces.

Results constrain neutron-rich matter in astrophysics.

Provides controlled theoretical uncertainties.

Abstract

Neutron matter presents a unique system for chiral effective field theory (EFT), because all many-body forces among neutrons are predicted to next-to-next-to-next-to-leading order (N3LO). We present the first complete N3LO calculation of the neutron matter energy. This includes the subleading three-nucleon (3N) forces for the first time and all leading four-nucleon (4N) forces. We find relatively large contributions from N3LO 3N forces. Our results provide constraints for neutron-rich matter in astrophysics with controlled theoretical uncertainties.