Eur. Phys. J. A (2005) 25: 115-135
https://doi.org/10.1140/epja/i2005-10067-5

Original Article

Double-pion photoproduction on nucleon and deuteron

Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099, Mainz, Germany

Received: 15 March 2005
Accepted: 23 May 2005
Published online: 22 July 2005

Abstract

Photoproduction of two pions on nucleon and deuteron is studied for photon energies from threshold up to E _γ = 1.5 GeV. For the elementary operator an effective Lagrangian approach is used with resonance and Born contributions. The model parameters are fixed by resonance decay widths and multipole analyses of single-pion photoproduction. A satisfactory description of total cross sections of two-pion production on the proton for various charge channels is achieved, except for π⁰π⁰ production for which a significant underestimation is found near threshold. The operator then serves for the evaluation of this reaction on the deuteron in the impulse approximation. In addition, NN rescattering in the final state is taken into account, but πN and ππ rescatterings are neglected. Results are presented for total cross sections and target asymmetries.