Spin response of neutron matter in ab initio approach

TL;DR

This paper introduces a new ab initio method to accurately compute the spin response of neutron matter, including uncertainty estimates, aiding astrophysical neutrino interaction studies.

Contribution

It develops a Gaussian integral transform-based approach within the ab initio framework to reconstruct response functions and estimate uncertainties.

Findings

Successful calculation of neutron matter spin response

Quantification of finite-size effects

Framework applicable to neutrino interaction studies

Abstract

We propose a general method embedded in the ab initio nuclear framework to reconstruct linear response functions and calculate sum rules. Within our approach, based on the Gaussian integral transform, we consistently treat the groundstate and the excited spectrum. Crucially, the method allows for a robust uncertainty estimation of the spectral reconstruction. We showcase it for the spin response in neutron matter. Our calculations are performed using state-of-the-art many-body coupled-cluster method and Hamiltonians derived in the chiral effective field theory, emphasizing the analysis of finite-size effects. This work serves as a stepping stone towards further studies of neutrino interactions in astrophysical environments from first principles.