Spin effects in large angle πp→ρp interactions

Using a model previously introduced to describe spin-spin asymmetries in large angle elastic proton-proton scattering, we have computed the helicity density matrix of ρ vector mesons produced in πp→ρp interactions, at 90° in the c.m. system. Contrary to most other schemes, we obtain some nondiagonal elements sizeably different from zero; when comparing the ρ^? decay angular distribution with experimental data we have an excellent agreement. We also give predictions for the case of ρ⁺ production.