Unitarization of the Veneziano Model, Pomeranchuk Singularity, and the Pion Mass

We suggest a general framework for unitarizing the Veneziano model for ππ scattering, and deduce some immediate consequences. By duality the unitarity s cut generates a moving Regge cut with branch-point trajectory 1+α^'t in the approximation m_π=0, with α^' the slope of the ρ-f⁰ trajectory. In principle m_π may be calculated from the shift of the Adler zero. A crude estimate yields m_π≈(α^')1/2m_ρΓ_ρ=95 MeV.