Constraining the nuclear energy density functional with quantum Monte Carlo calculations

TL;DR

This paper uses quantum Monte Carlo methods with chiral effective field theory interactions to study a neutron impurity, providing constraints on nuclear energy density functionals relevant to neutron-rich nuclei and astrophysical objects.

Contribution

It introduces a quantum Monte Carlo approach to constrain the time-odd components of nuclear energy density functionals using impurity behavior in polarized neutron matter.

Findings

Impurity behaves like a polaron in a unitary Fermi gas.

Results constrain time-odd parts of energy density functional.

Findings relevant to neutron stars and supernovae.

Abstract

We study the problem of an impurity in fully polarized (spin-up) low density neutron matter with the help of an accurate quantum Monte Carlo method in conjunction with a realistic nucleon-nucleon interaction derived from chiral effective field theory at next-to-next-to-leading-order. Our calculations show that the behavior of the proton spin-down impurity is very similar to that of a polaron in a fully polarized unitary Fermi gas. We show that our results can be used to put tight constraints on the time-odd parts of the energy density functional, independent of the time-even parts, in the density regime relevant to neutron-rich nuclei and compact astrophysical objects such as neutron stars and supernovae.