Paris nucleon-antinucleon potential constrained by recent antiprotonic-atom data and antineutron-proton total cross sections

TL;DR

This paper updates the Paris nucleon-antinucleon optical potential by incorporating recent experimental data, leading to improved modeling of nucleon-antinucleon interactions and the prediction of a broad quasibound state near threshold.

Contribution

The paper introduces a revised Paris nucleon-antinucleon potential that integrates new experimental data, enhancing the accuracy of interaction descriptions and predicting a novel quasibound state.

Findings

Improved fit to recent antiprotonic-hydrogen data and antineutron-proton cross sections.

Prediction of an isospin zero quasibound state at 4.8 MeV below threshold.

Enhanced description of nucleon-antinucleon interactions with updated potential.

Abstract

We report on an updated Paris nucleon-antinucleon optical potential. The long- and intermediate-range real parts are obtained by G-parity transformation of the Paris nucleon-nucleon potential based on a theoretical dispersion-relation treatment of the correlated and uncorrelated two-pion exchange. The short-range imaginary potential parametrization results from the calculation of the nucleon-antinucleon annihilation box diagram into two mesons with a nucleon-antinucleon intermediate state in the crossed channel. The parametrized real and imaginary short range parts are determined by fitting not only the existing experimental data included in the 1999 version of the Paris nucleon-antinucleon potential, but also the recent antiprotonic-hydrogen data and antineutron-proton total cross sections. The description of these new observables is improved. Only this readjusted potential generates an isospin zero 1S0, 52 MeV broad quasibound state at 4.8 MeV below the threshold. Recent BES data on J/psi decays could support the existence of such a state.