To which densities is spinpolarized neutron matter a weakly interacting Fermi gas?
Abstract
We study the properties of spinpolarized neutron matter at nexttonexttonexttoleading order in chiral effective field theory, including two, three, and fourneutron interactions. The energy of spinpolarized neutrons is remarkably close to a noninteracting 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 scatteringlength regime. Implications for energydensity 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.
 Publication:

Physics Letters B
 Pub Date:
 May 2015
 DOI:
 10.1016/j.physletb.2015.03.027
 arXiv:
 arXiv:1408.4168
 Bibcode:
 2015PhLB..744...18K
 Keywords:

 Nuclear Theory;
 Astrophysics  Solar and Stellar Astrophysics;
 High Energy Physics  Phenomenology
 EPrint:
 5 pages, 4 figures, minor changes, published version