Role of $K^*_0(700)$ exchange in the $p \bar{p} \to \Lambda \bar{\Lambda}$ reaction

TL;DR

This paper investigates the role of the $K^*_0(700)$ meson exchange in the $p ar{p} o \Lambda ar{\Lambda}$ reaction, demonstrating its importance in accurately modeling cross sections and providing insights into resonance contributions.

Contribution

It introduces the $K^*_0(700)$ meson exchange into the effective Lagrangian model for this reaction, highlighting its significant impact over traditional meson exchanges.

Findings

$K^*_0(700)$ exchange improves data fit across energy range.

The exchange plays a crucial role in matching total and differential cross sections.

Provides a framework to explore resonance effects at reaction threshold.

Abstract

Regarding the reaction $p \bar{p} \to \Lambda \bar{\Lambda}$, we provide a dynamical explanation focusing on its total and differential cross section based on the effective Lagrangian approach. Incorporating the $t$-channel exchange of the $K^*_0(700)$ meson and $s$-channel contribution from the vector excited state, we can reproduce the current experimental data fairly well in a wide energy region. Compared to the conventional $K$ and $K^*$ mesons exchange, the $K^*_0(700)$ meson exchange plays a more essential role in simultaneously capturing the observed features of the total and differential cross sections. This work gives a perspective to inspect the role of $K^*_0(700)$ and serves as a test to search for the resonances in the reaction $p \bar{p} \to \Lambda \bar{\Lambda}$ at threshold.