Electromagnetic properties of the πNN system: (I). The reaction γD → NNπ

The theory of the coupled \ensuremath{\pi}NN-NN systems is applied to the unified description of the \ensuremath{\pi}d-\ensuremath{\pi}d, \ensuremath{\pi}d-NN, and NN-NN reactions in the intermediate energy range. Off-shell modifications are introduced in the ${P}_{33}$ and ${P}_{11}$ \ensuremath{\pi}N channels and the effects of heavy meson exchange are investigated. In general, results for various observables are in agreement with experiments. We have assessed certain aspects upon which future work should improve.

Unified description of pi d- pi d, pi d-NN, and NN-NN reactions at intermediate energies.

The NN pi system is studied in a semi-relativistic model (non-relativistic nucleons and relativistic pions) where a Chew-Low Hamiltonian acts in the restricted space spanned by free N+N, N+N+ pi and N+N+2 pi states. The N+N ('absorption') and N+N+2 pi ('production') channels can be eliminated exactly, leaving an effective three-particle problem whose energy-dependent, absorptive interactions are known analytically. These represent a simple but non-trivial example of a mutually consistent set of forces for the NN pi problem, free of overcounting difficulties.

H. Garcilazo

Papers

Pion-deuteron elastic scattering in a relativistic three-body theory