high energy physics phenomenology

Role of exchange in the reaction

arXiv:2508.16912

summary

The paper uses an effective Lagrangian model to study the antiproton‑proton → Λ Λ̄ reaction, showing that t‑channel exchange of the scalar meson K*_0(700) together with s‑channel vector resonances can describe measured total and differential cross sections and Λ polarization.

Abstract

Based on the effective Lagrangian approach, we investigate the reaction. Within this framework, we provide a dynamical explanation by analyzing its total and differential cross sections, as well as the polarization of the produced hyperon. Incorporating the -channel exchange of the scalar and pseudoscalar mesons, complemented by an -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 and mesons exchange, the meson exchange plays a more essential role in simultaneously capturing the observed features of the total and differential cross sections. The introduction of the vector -channel resonance improves the description of the spin observables. This work gives a perspective to inspect the role of and serves as a test to search for the resonances in the reaction at threshold.

11 pages, 5 figures

Topics & keywords

#antiproton-proton annihilation#lambda hyperon production#meson exchange#scalar K*_0(700) role#effective Lagrangian approacheffective Lagrangiant-channel exchangeK*_0(700)differential cross sectionpolarizations-channel resonance