Cutoff-independent predictions from nuclear lattice effective field theory

TL;DR

This paper introduces a simple, cutoff-independent nuclear force model using only basic contact terms and a one-pion-exchange potential, achieving accurate predictions across various nuclei with minimal residual cutoff dependence.

Contribution

It presents a minimal chiral nuclear force that is remarkably cutoff independent, simplifying the EFT approach for nuclear structure calculations.

Findings

Accurately reproduces experimental binding energies up to calcium-40.

Exhibits small residual cutoff dependencies of only a few MeV.

Uses a lattice-inspired absolute-momentum regulator to suppress high-momentum modes.

Abstract

Cutoff independence is an essential requirement for the predictive power of nuclear \textit{ab initio} calculations based on effective field theory (EFT). While it is conventionally assumed that such invariance necessitates high-order interactions and complex many-body forces, we present a minimal chiral nuclear force that exhibits remarkable cutoff independence across a broad range from light to medium-mass nuclei and sub-saturated nuclear matter. Our framework comprises only contact terms up to next-to-leading order, a single three-nucleon contact force, and a leading-order one-pion-exchange potential, all constrained strictly in the $A \leq 3$ sector. Despite its simplicity, this interaction accurately reproduces experimental binding energies up to $^{40}\text{Ca}$ with unexpectedly small residual cutoff dependencies of only a few MeV. We demonstrate that the use of a lattice-inspired \emph{absolute}-momentum regulator efficiently suppresses high-momentum modes, resolving the overbinding problem for soft chiral forces without invoking complex many-body forces. These results establish a robust and economic foundation for EFT-based \textit{ab initio} calculations in both continuum and lattice frameworks.