Unitarity Constraints on effective interaction in $\pi N$ scattering

Abstract

Positivity constraints are derived on pion-nucleon scattering amplitudes and their even-order derivatives inside the Mandelstam Triangle with the help of dispersion relations. Fairly interesting constraints are obtained on some of the low energy constants, by a combination of the chiral perturbation theory for heavy baryons and existing fitting results from available pion-nucleon phase shifts at intermediate energies.

version to appear in Phys. Lett. B. 6 pages

References in corpus (8)

• Causality, Analyticity and an IR Obstruction to UV Completion
• Pion-nucleon scattering in chiral perturbation theory I: Isospin-symmetric case
• Aspects of chiral pion-nucleon physics
• The chiral effective pion-nucleon Lagrangian of order p^4
• Pion-nucleon scattering inside the Mandelstam triangle
• Pion-nucleon scattering in chiral perturbation theory II: Fourth order calculation
• Low energy analysis of pi N --> pi N
• Falsifying Models of New Physics Via WW Scattering

Cited by in corpus (5)

• Softness and Amplitudes' Positivity for Spinning Particles
• Aspects of the low-energy constants in the chiral Lagrangian for charmed mesons
• Sum Rules in the Standard Model Effective Field Theory from Helicity Amplitudes
• Meson-baryon effective chiral Lagrangians at order $p^4$
• Positivity constraints on the low-energy constants of the chiral pion-nucleon Lagrangian