FORM FACTORS, KRONECKER-DELTA TERMS, AND ABSORPTIVE PERIPHERAL MODEL

A prescription (OPE-δ) is introduced which enables one to obtain with little effort approximate results of absorption-model calculations for spin-space density matrix elements of unstable particles produced in high-energy quasi-two-body inelastic reactions. The OPE-δ method does not involve a partial-wave expansion. It consists of dropping those parts of the OPE amplitudes which would otherwise lead to Kronecker-δ contributions to the partial-wave amplitudes. The method is partially justified by studying results of one-pion-exchange-absorption calculations with and without form factors. Explicit calculations are presented for the reaction π-+p→ρ-+p at 3 BeV/c. © 1969 The American Physical Society.