Effect of Pion-Pion Scattering Resonance on Nucleon Structure and Pion-Nucleon Scattering at Low Energies
نویسنده
چکیده
The effect of pion-pion scattering resonance on the isovector part of nucleon structure is analysed by a method similar to that of Frazer and Fulco, but with one more subtraction for dispersion relations on helicity amplitudes of nucleon·aritinucleon production process in order to remedy the divergence regarding the left-hand cut. If the subtracted spectral representations are used for the form factors, G1v(t) and G2v(t), and the narrow resonance is assumed for the P·wave pion·pion scattering, then the form factors can be written in the form given by Clemente! and Villi and the square of pion-pion scattering resonance energy is required to be 18-25 p.2. The effect of this resonance on pion-nucleon scattering at low energy regions is shown to be not inconsistent with the experimental data, if we use the subtracted form for the pion-pion terms in the dispersion relations for pion-nucleon scat· tering amplitudes.
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