Renormalization of One-Pion Exchange in Chiral Effective Field Theory for Antinucleon-Nucleon Scattering

TL;DR

This paper studies the renormalization process of one-pion exchange in chiral effective field theory for antinucleon-nucleon scattering, revealing the need for additional contact interactions and comparing results with experimental data.

Contribution

It demonstrates that renormalization in $ar{N}N$ scattering requires more contact interactions than naive expectations and compares these findings with nucleon-nucleon systems.

Findings

Renormalization necessitates extra contact interactions.

Results align with energy-dependent partial-wave analysis.

Comparison with nucleon-nucleon applications shows similarities.

Abstract

The renormalization of iterated one-pion exchange (OPE) is studied in Chiral Effective Field Theory ($\chi$EFT) for the antinucleon-nucleon ($\overline{N}\!N$) system. The OPE potential is cut off at a certain distance and contact interactions are represented by a complex spherical well with the same radius. We investigate the dependence on the cutoff radius of the phase shifts, inelasticities, and mixing angles for the low partial waves in $\overline{N}\!N$ scattering. We show that renormalization requires additional contact interactions compared to the expectation based on naive dimensional analysis. Results after renormalization are compared with the state-of-the-art energy-dependent partial-wave analysis of $\overline{N}\!N$ data. We compare our conclusions with applications of $\chi$EFT to the nucleon-nucleon system.