The Theoretical Study of ${\pi }^{+}p\to p{a}_0^{+}\phi$ Reaction

We study the production of hyperon resonances in the ${\pi }^{+}p\to p{a}_0^{+}\phi$ reaction within an effective Lagrangian approach. The model includes the production of $\mathrm{\Delta }(1940)$ and $\mathrm{\Delta }(1920)$ in the intermediate state excited by the $\rho$ and $p$ exchanges between the initial proton and $\pi$ meson. Due to the large contribution of $\rho$ exchange in $\mathrm{\Delta }(1940)$ production, $\mathrm{\Delta }(1940)$ is found a significant contribution near the threshold in this reaction. We provide total and differential cross section predictions for the reation and discuss the possible influence of model parameters, off-shell effects and branching ratios for $\mathrm{\Delta }(1940)\to p{a}_0$ and $\mathrm{\Delta }(1920)\to p{a}_0$ decays, which will be useful in future experimental studies. This reaction can provide a platform for studying the features of $\mathrm{\Delta }(1940)$ resonance, especially the coupling to $p{a}_0$ channel.