Large-cutoff behavior of local chiral effective field theory interactions

TL;DR

This paper studies how local chiral effective field theory interactions behave at different cutoff scales, finding conditions under which they become independent of the cutoff, which could improve nuclear calculations.

Contribution

It identifies specific leading-order operators that lead to cutoff-independent phase shifts and deuteron energies across various regulators, enhancing chiral Hamiltonian applications.

Findings

Phase shifts and deuteron energy converge to cutoff-independent plateaus.

Certain leading-order operators yield regulator-independent results.

Potential for improved calculations with three-nucleon interactions.

Abstract

Interactions from chiral effective field theory have been successfully employed in a broad range of \textit{ab initio} calculations of nuclei and nuclear matter, but it has been observed that most results of few- and many-body calculations experience a substantial residual regulator and cutoff dependence. In this work, we investigate the behavior of local chiral potentials at leading order under variation of the cutoff scale for different local regulators. When varying the cutoff, we require that the resulting interaction produces no spurious bound states in the deuteron channel. We find that, for a particular choice of leading-order operators, nucleon-nucleon phase shifts and the deuteron ground-state energy converge to cutoff-independent plateaus, for all regulator functions we investigate. This observation may enable improved calculations with chiral Hamiltonians that also include three-nucleon interactions.