Optimal Fermi-averaging t-matrix for (${\pi }^{+}$,$K^{+}$) reactions in $\Lambda$ quasi-free region

T. Harada, Y. Hirabayashi

We propose an optimal Fermi-averaging for an elementary ${\pi }^{+}$+$n$$\to$$K^{+}$+$\Lambda$ t-matrix under the on-energy-shell condition, in order to describe (${\pi }^{+}$,$K^{+}$) reactions on a nucl…