The Theoretical Study of $\Sigma^{+} p \to\Lambda a_0^{+} p$ Reaction

We conducted a theoretical study on the process $\Sigma^{+} p \to\Lambda a_0^{+} p$ based on an effective Lagrangian approach. This model encompasses the excitation of intermediate states leading to the production of $\Delta(1920)$ through $\pi^{+}$ and $K^{+}$ meson exchanges between the initial $\Sigma^{+}$ baryon and the initial proton $p$, as well as the generation of $\Delta(1940)$ via $\pi^{+}$ and $\rho^{+}$ meson exchanges. We provide predictions for the total and differential cross sections and discuss the potential impacts of cutoff parameters, off-shell effects, and branching ratios on the $\Delta^{\ast} \to a_0 p$ decay. Given the dominance of $\Delta(1940)$ in the region close to the reaction threshold, this reaction is considered an ideal platform for deeply exploring the unique properties of the $\Delta(1940)$ resonance. Through this approach, we can gain a more precise understanding of the intrinsic characteristics of this particle.