Exclusive π⁺d→ηpp process

We calculate the exclusive cross section of the process π⁺d→ηpp in the energy region T_π775 MeV in order to study the effect of the ηN→ηN final-state interaction in the region of the N(1535)S₁₁ resonance. Our model includes first- and second-order diagrams involving πN→πN, πN→ηN, ηN→ηN, and NN→NN interactions. The sensitivity of the cross section to different parametrizations of the less-known ηN final-state interaction is studied.