Mr Eduardo Reis (UFSJ)
This work presents the first results of an extension of the spectral quark model which includes different flavors. The spectral quark model is an approach based on a generalization of the Lehmann representation for the quark propagator. Electromagnetic and chiral invariance are ensured with the help of gauge technique which provides particular solutions to the Ward-Takahashi identities. General conditions on the quark spectral function follow from natural physical requirements. In particular, the function is normalized, it’s all positive moments must vanish, while the physical observables depend on negative moments and so-called log moments. As a consequence, the model is made finite. The inclusion of different flavors of quarks in the model, from the determination of the two different spectral functions and n-point functions constructed from Ward-Takahashi identities, permits the physical description of meson kaon, considered a light meson constituted by an up and strange quark. A large number of predictions and relations were deduced from our approach, as quark condensate, vacuum polarization, weak decay and form factors for light mesons.