Pole structure inference of Λ(1405) via deep learning in the Σ⁰π⁰ invariant mass spectrum

Abstract

Peak structures in invariant mass distributions are often interpreted as genuine hadronic resonances. However, its existence near a hadron-hadron threshold results to ambiguous interpretations such as bound and virtual states as dynamical and kinematical effects come into play. These states can be inferred by studying the pole structure of the S-matrix. In this work, we analyzed one of these enhancements that is the Λ(1405) observed near the K̅N-threshold in the Σ⁰π⁰ invariant mass distribution from CLAS measurements of the γp → K⁺Σ⁰π⁰ reaction. Using a convolutional neural network, our results show that the Λ(1405) is a two-pole structure of the S-matrix in the second Riemann sheet and can be interpreted as a bound state of K̅ and N.