Coupling of \bar K*N to the Lambda(1520)

Abstract

We study the coupling of the Lambda(1520)= Lambda* resonance to the \bar K* vector meson and nucleon. This coupling is not directly measured from the resonance decay, but is expected to be important in hyperon production reactions, in particular for the exotic Theta+ production. We compute the coupling in two different schemes, one in the chiral unitary model where the Lambda* is dominated by the quasibound state of mesons and baryons, and the other in the quark model where the resonance is a p-wave excitation in the three valence quarks. Although it is possible to construct both models such that they reproduce the \bar K N and pi Sigma decays, there is a significant difference between the Lambda* \bar K* N couplings in the two models. In the chiral unitary model $|g_{Λ^*\bar{K}^* N}| \sim 1.5$, while in the quark model $|g_{Λ^*\bar{K}^* N}| \sim 10$. The difference of the results stems from the different structure of the Lambda* in both models, and hence, an experimental determination of this coupling would shed light on the nature of the resonance.