Neutron matter from local chiral EFT interactions at large cutoffs*

Neutron matter is an important many-body system that provides valuable constraints for the equation of state (EOS) of neutron stars. Neutron-matter calculations employing chiral effective field theory (EFT) interactions have been used extensively in the past for this purpose. Among the various many-body methods used, quantum Monte Carlo (QMC) methods stand out due to their nonperturbative nature and their accuracy and precision. However, QMC methods require local interactions as input, which leads to the appearance of stronger regulator artifacts as compared to non-local interactions. 

In this talk, I will discuss how to employ high-cutoff interactions from chiral EFT (400 MeV ≤ Λ ≤ 700 MeV) in studies of pure neutron matter. These interactions have been adjusted to two-nucleon phase shifts, the triton binding energy, as well as the triton beta-decay half life. I will discuss how regulator artifacts significantly decrease with cutoff, leading to a dramatic reduction of uncertainties in the neutron-matter EOS, and discuss implications for astrophysical observables.