Studying $\Lambda^*$ resonances in the $p \bar p \rightarrow \Lambda \bar\Lambda \eta$ reaction

TL;DR

This paper provides a theoretical analysis of the $p ar p ightarrow ar ext{Lambda} ext{Lambda} ext{eta}$ reaction, predicting cross sections and distributions to explore $ ext{Lambda}$ resonances and their couplings, aiding experimental studies.

Contribution

It introduces a novel theoretical approach to study $ ext{Lambda}$ resonances via the $p ar p$ reaction, emphasizing the reaction's potential to verify narrow $ ext{Lambda}$ states and their couplings.

Findings

Predicted total cross sections and angular distributions.

Identified the reaction's sensitivity to $ ext{Lambda}$ resonances.

Suggested experimental data can complement existing scattering data.

Abstract

In this work, we make a theoretical study on the $p \bar p \rightarrow \Lambda \bar\Lambda \eta$ reaction for antiproton beam energy from threshold to 4GeV within an effective Lagrangian approach and isobar model. By assuming this reaction is dominated by the excitation of $\Lambda$ and $\bar \Lambda$ resonances in intermediate states, we calculate the total cross sections and give the predictions of the angular distribution and invariant mass spectrum of final particles. In particular, we discuss the possibility to verify the existence of a narrow $\Lambda$ resonance found in the process of $K^- p\to \eta \Lambda$ in the present reaction. It shows that the $p \bar p \rightarrow \bar \Lambda \Lambda \eta$ reaction can provide us with valuable information about the $\Lambda$ resonances having significant couplings to $\bar K N$ and $\Lambda\eta$ channels. Thus the experimental data of this reaction will be a good supplement to the $\bar K N\to\eta \Lambda$ scattering data for studying $\Lambda$ resonances.