$Lambda(1405)$ Photoproduction via $gamma p to K^+pi^+Sigma^-$

Abstract

In this work, we perform a $toy-model$ analysis for the unpolarized photoproduction of $\Lambda(1405)\equiv\Lambda^*$ by employing the effective Lagrangian approach at the tree level. We consider that $\Lambda^*$ consists of high- and low-mass poles as suggested by the chiral unitary model (ChUM). We determine all the model parameters for the phenomenological strong form factors by using theoretical information from the ChUM and experimental data. From the numerical calculations, we observe that the interference between the two poles turns out to be destructive, resulting in a single-peak line at $M_{\pi^+\Sigma^-}\approx 1405$ MeV in the invariant mass distribution. From this observation, we conclude that the interference patterns for the two poles should follow those suggested by the ChUM.