Pion nucleon scattering and pion photoproduction. Dynamical models

A. MARIANO

Buenos Aires

Simposio; Latin –american Workshop on Fundamental Interactions; 2004

Universidad de Buenos Aires

Motivation • Properties of the majority of baryonic resonances are badly known • Properties of the majority of baryonic resonances are badly known * Conservative intervals are provided for most of the  masses and widths (Breit-Wigner formula or pole position parameters) * Other parameters characterizing baryonic resonances areeven less known (multipole moments) • Confiable determination of parameters for baryonic resonances to compare with values coming from quark models • Built up an effective Lagrangian model that fulfills basics constrains * Incorporates relevant hadronic degrees of freedom * Respects electromagnetic gauge invariance when finitewidth effects are incorporated (resonances) * Respects invariance under contact transformations (highspin particles) * Unitarity * Consistent description of reactions induced by hadronicprobes(elastic scattering, Bremmstrahlung, pion production)with those induced by electromagnetic probes (photoproduction, electroproduction