Beyond One-Particle Exchange

Double-particle exchange in hadronic interactions is investigated with an extension of our strong-absorption model. All parameters are taken from single-particle-exchange fits. Spin effects, variations in coupling values, and unavoidable cancelations result in a cross-section range of ∼ ${10}^5$ for different forward reactions, in good agreement with existing data. Reactions with exotic-quantum-number exchange are small because of spin and symmetry coupling properties of particles, while some nonexotic double-particle exchanges are quite large.