Nucleon-nucleon resonances at intermediate energies using a complex energy formalism

TL;DR

This paper employs a complex scaling method to identify nucleon-nucleon resonances at intermediate energies, revealing narrow-width resonances supported by realistic potentials beyond their initial fit regions.

Contribution

It introduces a complex energy formalism applicable to various potentials for locating nucleon-nucleon resonances at energies up to 2 GeV.

Findings

Realistic potentials support resonances above their fit regions.

Some resonances have narrow widths relative to their energy.

Resonances are identified using complex scaling at intermediate energies.

Abstract

We apply our method of complex scaling, valid for a general class of potentials, in a search for nucleon-nucleon S-matrix poles up to 2 GeV laboratory kinetic energy. We find that the realistic potentials JISP16, constructed from inverse scattering, and chiral field theory potentials N$^3$LO and N$^2$LO$_{opt}$ support resonances in energy regions well above their fit regions. In some cases these resonances have widths that are narrow when compared with the real part of the S-matrix pole.