The role of the $\Lambda(1405)$ in the $pp\to p K^+\Lambda(1405)$ reaction

TL;DR

This paper presents a theoretical analysis of the $pp o p K^+\Lambda(1405)$ reaction, highlighting the roles of different meson exchanges and the two-pole structure of $\Lambda(1405)$, aligning well with recent experimental data.

Contribution

It introduces a comprehensive theoretical model including kaon, pion, and rho exchanges, accounting for the two-pole structure of $\Lambda(1405)$, to explain the reaction's shape and cross section.

Findings

The model reproduces the shape of the reaction distribution.

Total cross section aligns with experimental data.

Different meson exchanges contribute distinctively to the reaction.

Abstract

We report a theoretical study of the $pp\to p K^+\Lambda(1405)$ reaction, which was recently investigated at COSY-J\"{u}lich by using a 3.65 GeV/c circulating proton beam incident on an internal hydrogen target. The reaction is driven by single kaon exchange, single pion exchange, and single rho exchange terms which have very different shapes due to the two pole structure of the $\Lambda(1405)$ and the presence of background terms. The shape for the sum of the three contributions, as well as the total cross section, are consistent with present data within experimental and theoretical uncertainties, using reasonable form factors for the meson-baryon vertices.