6533b838fe1ef96bd12a44a0

RESEARCH PRODUCT

Chiral approach to the two pion decay of the Roper

E. HernándezM. J. Vicente VacasEulogio Oset

subject

PhysicsNuclear and High Energy PhysicsParticle physicsChiral perturbation theoryBethe–Salpeter equationMesonHigh Energy Physics::PhenomenologyNuclear TheoryHadronElementary particleParticle decayPionInvariant massNuclear Experiment

description

Abstract The analysis of Manley and collaborators [1] of the decay of the Roper into two pions requires the introduction of an effective scalar-isosclar ϵ or σ meson in order to describe the s-wave ππ interaction. Here we try to understand at a more fundamental level the origin of this effective channel. In our model the two pions are produced in single pion-baryon-baryon vertices and their re-scattering in the L=0, I=0 channel is explicitly evaluated. For that purpose we use unitarized chiral perturbation theory to obtain the Bethe-Salpeter amplitude for the two pion re-scattering in the appropriate channel. Our model produces invariant mass distributions in agreement with the ones obtained in Manley's approach.

https://doi.org/10.1016/s0375-9474(03)01126-6