Near Threshold Enhancement of p pbar System and p pbar Elastic Scattering

TL;DR

This paper develops an effective theory to explain the near-threshold enhancement in proton-antiproton production and elastic scattering, emphasizing the role of final state interactions and rescattering processes.

Contribution

It introduces a novel effective theory for Nar N interactions near threshold, incorporating systematic rescattering corrections to describe experimental enhancements.

Findings

Successfully describes p pbar threshold enhancement in decays and annihilations.

Provides a framework for calculating Nar N elastic scattering amplitudes.

Highlights the importance of rescattering corrections in near-threshold phenomena.

Abstract

The observed enhancement of $p\bar p$-production near the threshold in radiative decays of $J/\psi$ and $e^+e^-$-annihilations can be explained with final state interactions among the produced $N\bar N$ system, where the enhancement is essentially determined by $N\bar N$ elastic scattering amplitudes. We propose to use an effective theory for interactions in a $N\bar N$ system near its threshold. The effective theory is similar to the well-known one for interactions in a $NN$ system but with distinctions. It is interesting to note that in the effective theory some corrections to scattering amplitudes at tree-level can systematically be summed into a simple form. These corrections are from rescattering processes. With these corrected amplitudes we are able to describe the enhancement near the threshold in radiative decays of $J/\psi$ and $e^+e^-$-annihilations, and the $p\bar p$ elastic scattering near the threshold.