Speaker
Mr
Hugo Garcia-Tecocoatzi
(Instituto de Ciencias Nucleares UNAM Mexico City)
Description
We study electromagnetic couplings of baryons in an extension of the
quark model, called the Unquenched Quark Model (UQM), in which the
contributions of the quark-antiquark pairs are taken into account
explicitly. The interaction Hamiltonian is obtained from quantum field
theory in the nonrelativistic limit and includes electromagnetic transitions between
quarks and antiquarks, as well as creation and annihilation processes of
quark-antiquark pairs. Previous studies of the UQM were carried out for
observables (flavor asymmetry, baryon spin and magnetic moments) that do not change the number of quarks and antiquarks. This is the first time that the contributions of creation and annihilation processes are taken into account. The total
interaction Hamiltonian is relevant for both photo- and electro-production
of baryon resonances and electromagnetic decays of baryons. As an
application we study the electromagnetic decays of decuplet baryons which can not be
explained satisfactorily in the constituent quark model.
Primary author
Mr
Hugo Garcia-Tecocoatzi
(Instituto de Ciencias Nucleares UNAM Mexico City)
