Studies of Di-proton production at ANKE.

The study of NN-interactions with production of ¹S₀ proton pairs (diprotons) provides a new approach to hadron interactions at intermediate energies. The use of the polarised COSY beams and the ANKE polarised internal target allows one to conduct single and double polarization experiments. A number of processes including pd→{pp}_sn, production of one and two pions in pN collisions, and the pp→{pp}_sγ process, have been investigated. Information on the near-threshold single pion production with formation of a diproton in the processes pp→{pp}_sπ⁰ and pn→{pp}_sπ^- is urgently needed for further development of chiral perturbation theory. The measurements of dσ/dΩ, A_y and the spin-correlation coefficients A_x,x and A_x,z will permit an amplitude analysis that should provide a non-trivial test of the χPT predictions. A combined study of these processes will lead to the isolation of the strength parameter d of the four-nucleon-pion contact interaction in χPT. Preliminary ANKE results on dσ/dΩ and A_y in these processes are presented, and the future experimental programme is discussed. [ABSTRACT FROM AUTHOR]