the width of the roper resonance in baryon chiral perturbation theory
;Jambul Gegelia;Ulf-G. Meißner;De-Liang Yao
ACS chemical biology2016Vol. 760pp. 736-741
125
gegelia2016physicsthe
Abstract
We calculate the width of the Roper resonance at next-to-leading order in a systematic expansion of baryon chiral perturbation theory with pions, nucleons, and the delta and Roper resonances as dynamical degrees of freedom. Three unknown low-energy constants contribute up to the given order. One of them can be fixed by reproducing the empirical value for the width of the Roper decay into a pion and a nucleon. Assuming that the remaining two couplings of the Roper interaction take values equal to those of the nucleon, the result for the width of the Roper decaying into a nucleon and two pions is consistent with the experimental value.