Role of meson-meson correlation effects in the NN → ϱπ annihilation process

Abstract Meson-meson correlation effects are investigated in the N N → ϱπ annihilation process using a realistic meson-exchange model for the ϱπ interaction determined previously, together with a conventional baryon-exchange transition model and a consistent N N interaction. For N N S- states , they have a drastic effect and bring the relative ( 1 S 0 3 S 1 ) branching ratio up to the experimental value, thus offering an explanation for the long-standing so-called “ϱπ” puzzle. For N N P- states , their effect is of minor importance, and discrepancies remain for those ratios involving annihilation from the N N( 3 P J ) state to ϱπ(l′ = 2).