Portal de Periódicos da CAPES

Unitary meson-exchange π NN models: NN and π d elastic scattering

1987; American Institute of Physics; Volume: 36; Issue: 4 Linguagem: Inglês

10.1103/physrevc.36.1459

1538-4497

T.-S. H. Lee, Akihiko Matsuyama,

High-Energy Particle Collisions Research

Within a unitary \ensuremath{\pi}NN theory a set of coupled integral equations defined in the NN\ensuremath{\bigoplus}N\ensuremath{\Delta} \ensuremath{\bigoplus}\ensuremath{\pi}NN subspace has been derived for examining the extent to which the NN and \ensuremath{\pi}d elastic scattering data can be both described by a class of meson-exchange \ensuremath{\pi}NN models. The considered models are constructued by using a previously developed subtraction procedure to extend the Paris, Bonn, Argonne-V14, and Reid NN potentials to include the coupling to the \ensuremath{\pi}NN production channel. The pion production through the \ensuremath{\Delta} excitation is described by a \ensuremath{\pi}N\ensuremath{\leftrightarrows}\ensuremath{\Delta} vertex and a ${V}_{\mathrm{NN}\mathit{\ensuremath{\leftrightarrows}}\mathrm{N}\mathit{\ensuremath{\Delta}}}$ transition potential, while the production through nonresonant \ensuremath{\pi}N interactions is described by a transition operator ${F}_{\ensuremath{\pi}\mathrm{NN}\mathit{\ensuremath{\leftrightarrows}}\mathrm{NN}}$. It is found that none of the constructed models can accurately reproduce all NN and \ensuremath{\pi}d elastic scattering data, in particularly the data of polarization observables. Our results indicate that either the conventional phenomenological parametrizations of baryon-baryon interaction at short distances are not valid in the intermediate energy region, or some genuine quark dynamics has already been revealed in the \ensuremath{\pi}NN data.