Pi rho scattering and the pi NN form factor.

Abstract

We investigate \ensuremath{\pi}\ensuremath{\rho} scattering in the pseudoscalar (\ensuremath{\pi}) and axial-vector (${\mathit{A}}_{1}$) channel. Our model based on s- as well as t-channel meson exchange can resolve apparent discrepancies occurring in the analysis of the axial-vector ${\mathit{A}}_{1}$ meson. Furthermore, it leads to an appreciable softening of the \ensuremath{\pi}NN form factor in agreement with information from other sources. This strong contribution in the pionic channel substantiates earlier claims that inclusion of correlated \ensuremath{\pi}\ensuremath{\rho} exchange might allow the use of a soft \ensuremath{\pi}NN form factor in NN potential models and thus could resolve a long-standing puzzle.