engleski

Schwinger-Dyson approach, gluon condensates and phenomenology of eta-eta' complex

The Schwinger-Dyson approach to hadron phenomenology requires a rather strong enhancement (at intermediate spacelike momenta of the order Q2 ~ 0.5 GeV2) of the "infrared part" of the quark-gluon interaction. So far, such phenomenologically successful enahnced part has to be modeled, since it has been difficult to explain theoretically. A mechanism based on gluon condensates may provide an essential contribution to the effective quark-gluon interaction, since we have strong evidence that this leads to an enhancement which gives sufficiently strong dynamical chiral symmetry breaking, crucial for describing the light pseudoscalar mesons. This has been shown in the nonstrange sector by obtaining good values of dynamically generated quark mass, chiral quark condensate, pion decay constant and pion mass, as well as satisfying Gell-Mann-Oakes-Renner relation. We can demonstrate the extension thereof into the strange sector, which enables a good description not only of kaons, but of the eta-eta' complex as well.

hadron; quark; gluon; Dyson-Schwinger equations; QCD

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