Meson-baryon scattering lengths without annihilation diagrams to order $p^4$ in heavy baryon chiral perturbation theory

Jing Ou-Yang, Ke Wang, Bo-Lin Huang

We calculate the threshold $T$ matrices of the meson and baryon processes that have no annihilation diagrams: ${\pi }^{+}{\Sigma }^{+}$, ${\pi }^{+}{\Xi }^0$, $K^{+}p$, $K^{+}n$, and ${\bar{K}}^0{\Xi }^0$ to the fo…