We study the properties of spin-polarized neutron matter at next-to-next-to-next-to-leading order in chiral effective field theory, including two-, three-, and four-neutron interactions. The energy of spin-polarized neutrons is remarkably close to a non-interacting system at least up to saturation density, where interaction effects provide less than 10% corrections. This shows that the physics of neutron matter is similar to a unitary gas well beyond the scattering-length regime. Implications for energy-density functionals and for a possible ferromagnetic transition in neutron stars are discussed. Our predictions can be tested with lattice QCD, and we present results for varying pion mass.
Physics Letters B
- Pub Date:
- May 2015
- Nuclear Theory;
- Astrophysics - Solar and Stellar Astrophysics;
- High Energy Physics - Phenomenology
- 5 pages, 4 figures, minor changes, published version