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Title: Pion-nucleon scattering and the [pi][ital NN] coupling constant in the chiral color dielectric model

Journal Article · · Physical Review, C (Nuclear Physics); (United States)
; ;  [1]
  1. Department of Physics, Oregon State University, Corvallis, Oregon 97331 (United States)

We apply the chiral color dielectric model to low- and medium-energy scattering within the coupled [pi][ital N] and [pi][Delta] system. Dynamic baryon states in which quarks are confined by the scalar color dielectric field are constructed in Fock space. Spurious motion of the center of mass is eliminated by constructing momentum eigenstates via a Peierls-Yoccoz projection. The relativistic Lippmann-Schwinger equation is solved for the complex energies of the [ital T] matrix poles, and the pole positions of the nucleon and delta are used to fix the few parameters of the model. The [ital S]- and [ital P]-wave phase shifts, the bare [ital N] and [Delta] masses, the renormalized [pi][ital NN] and [pi][ital N][Delta] coupling constants, and the [pi][ital NN] and [pi][ital N][Delta] vertex functions are predicted. We conclude that the monopole form factors often found in the literature are inadequate for reproducing [pi][ital N] scattering, and that more realistic ones such as those from the color dielectric model are needed. We also conclude that the radius parameter of the form factor is more than twice as large as that preferred by meson exchange potential models. By renormalizing the [pi][ital N] vertex by the pion field, the ratio of the [pi][ital N][Delta] to [pi][ital NN] coupling constants is closer to experiment than the SU(6) prediction.

OSTI ID:
6474719
Journal Information:
Physical Review, C (Nuclear Physics); (United States), Vol. 51:4; ISSN 0556-2813
Country of Publication:
United States
Language:
English