Low energy single pion production processesπN→ππN

Abstract

Using baryon chiral perturbation theory (B$\chi$PTh), explicitly including the $\Delta$(1232) and $N^{*}$(1440) baryon resonances only, we compute for incoming ${\pi }^{\pm }P$ channels with kinetic energy under 400 MeV, total cross sections, angular distributions, and various final state correlation functions and compare these with available experimental data in this energy range. Threshold isospin amplitudes are extracted from the calculated fully covariant perturbative amplitudes. No attempt is made to fit this data. The necessary input parameters were all taken from separate experimental data. The results appear to be generally encouraging for $\mathrm{B}\chi \mathrm{PTh}$.