Theory of time-like baryon form factors near thresholds

TL;DR

This paper proposes a nonperturbative mechanism for baryon-antibaryon production near thresholds, explaining resonance effects and angular dependencies in electroproduction cross sections without fitting parameters.

Contribution

It introduces a new theoretical model for baryon production near thresholds that accounts for resonance effects and angular dependencies without requiring parameter fitting.

Findings

Resonances like $ ext{ψ}(4S)$ and $ ext{Υ}(6S)$ explain cross section enhancements.

Intermediate D-wave resonances cause angular dependence in differential cross sections.

The model explains the unusual behavior of the proton's $G_E/G_M$ ratio.

Abstract

A new mechanism of baryon-antibaryon production via nonperturbative double pair creation in intermediate mesons is proposed and the theory contains no fitting parameters. It is shown, that near-threshold resonances are responsible for enhancements in electroproduction cross sections: $\psi(4S)$ for $\Lambda^+_c \Lambda^-_c, \Upsilon (6S)$ for $\Lambda_b \bar \Lambda_b$. An admixture of intermediate $D$- wave resonances produces angular dependence in differential cross section and can explain unusual behavior of the ratio $G_E/G_M$ for the proton.