Isovector electromagnetic exchange currents in the chiral approach

摘要: The problem studied in the paper concerns structure of isovector e.m. MEC operators A1−, ϱ- and π ranges interval intermediate energies. two main dynamic principles which we invoke our considerations are current conservation gauge chiral invariance. Respecting them consistently allows us to describe correctly interaction NA1 ϱπ system with external field. Our results as follows: (i) We verified that Lagrangian approach is consistent prediction low energy theorem at threshold. (ii) We showed explicitly continuity equation longitudinal parts currents obey. (iii) We proved equivalence relation for operator pion range demonstrated existence seagull built up using PS πN coupling. This new term influences strongly exchange charge density.