Testing the nature of the $\Lambda$(1520) in the $J/\psi\to\bar{\Lambda}K^-p$ and $J/\psi\to\bar{\Lambda}\pi^+\pi^-\Lambda$ reactions

TL;DR

This paper predicts a ratio of invariant mass distributions at the $ ext{Lambda}(1520)$ peak in specific $J/\psi$ decay reactions, aiming to test the chiral unitary approach's description of this resonance.

Contribution

It introduces a model-independent prediction for the invariant mass ratio at the $ ext{Lambda}(1520)$ peak to probe its properties and couplings, testing the dynamically generated resonance hypothesis.

Findings

Predicts the invariant mass distribution ratio at the $ ext{Lambda}(1520)$ peak.

Provides a method to extract $ ext{Lambda}(1520)$ couplings from experimental data.

Supports the dynamically generated nature of the $ ext{Lambda}(1520)$ resonance.

Abstract

We study the reactions $J/\psi\to\bar{\Lambda}K^-p$ and $J/\psi\to\bar{\Lambda}\pi^+\pi^-\Lambda$ with a unitary chiral approach. We predict the ratio of the invariant mass distributions of these two reactions at the $\Lambda(1520)$ peak position, which is free of the unknown production mechanism and reflects only the properties of the $\Lambda(1520)$. An experimental measurement of this ratio will provide the couplings of the $\Lambda(1520)$ to its decay channels, allowing to test the predictions of the chiral unitary approach on this resonance, which appears as dynamically generated in that approach.