Abstract
We discuss the two-pion-exchange (TPE) potential which emerges from a box diagram with one nucleon (the spectator) restricted to its mass shell, and the other nucleon line replaced by a subtracted, covariant \ensuremath{\pi}N scattering amplitude which includes \ensuremath{\Delta}, Roper, and ${\mathit{D}}_{13}$ isobars, as well as contact terms and off-shell (nonpole) dressed nucleon terms. The \ensuremath{\pi}N amplitude satisfies chiral symmetry constraints and fits \ensuremath{\pi}N data below \ensuremath{\sim} 700 MeV pion energy. We find that this TPE potential can be well approximated by the exchange of an effective sigma and delta meson, with parameters close to the ones used in one-boson-exchange models that fit NN data below the pion production threshold. \textcopyright{} 1996 The American Physical Society.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
