Parity nonconserving two-pion exchange in elastic pp scattering is
investigated in the presence of phenomenological strong distortions in various
models. Parity violation is included in the nucleon-pion vertex considering NN
and N Delta(1232) intermediate states in box and crossed box diagrams. Using
the derived parity nonconserving two-pion exchange potential we calculate the
longitudinal analyzing power A_L in elastic pp scattering. The predicted
effect is of the same order as vector meson exchanges.Comment: 13 pages, 8 eps figure