Low-energy theorems for nucleon-nucleon scattering at unphysical pion masses

TL;DR

This paper extends low-energy theorems for nucleon-nucleon scattering to unphysical pion masses, providing correlations between effective range expansion coefficients relevant for lattice QCD simulations.

Contribution

It generalizes low-energy theorems to unphysical pion masses up to 400 MeV, aiding interpretation of lattice QCD results.

Findings

Correlations between effective range coefficients are established for unphysical pion masses.

Results are applicable to lattice QCD simulations of two-nucleon systems.

Implications for understanding nuclear forces at different pion masses.

Abstract

The longest-range part of the nuclear force due to the one-pion exchange governs the energy dependence of the scattering amplitude in the near-threshold region and imposes correlations between the coefficients in the effective range expansion. These correlations may be regarded as low-energy theorems and are known to hold to a high accuracy in the neutron-proton 3S1 partial wave. We generalize the low-energy theorems to the case of unphysical pion masses and provide results for the correlations between the coefficients in the effective range expansion in this partial wave for pion masses up to Mpi ~ 400 MeV. We discuss the implications of our findings for the available and upcoming lattice-QCD simulations of two-nucleon observables.