Evaluation of the Pion-Nucleon Sigma Term from CHAOS Data

Abstract: We have reanalyzed the $\pi ^{\pm} p$ scattering data at low energy in the Coulomb-nuclear interference region as measured by the CHAOS group at TRIUMF with the aim to determine the pion-nucleon $\sigma$ term. The resulting value $\sigma=(44\pm 12)$ MeV, while in agreement with lattice QCD calculations and compatible with other recent analyses, is significantly lower than that from the GWU-TRIUMF analysis of 2002.