Probing the Gluon Self-Interaction in Light Mesons

Institute for Nuclear Physics, Darmstadt University of Technology, 64289 Darmstadt, Germany.
Physical Review Letters (Impact Factor: 7.51). 09/2009; 103(12):122001. DOI: 10.1103/PHYSREVLETT.103.122001
Source: PubMed


We investigate masses and decay constants of light mesons from a coupled system of Dyson-Schwinger and Bethe-Salpeter equations. We explicitly take into account dominant non-Abelian contributions to the dressed quark-gluon vertex stemming from the gluon self-interaction. We construct the corresponding Bethe-Salpeter kernel that satisfies the axial-vector Ward-Takahashi identity. Our numerical treatment fully includes all momentum dependencies with all equations solved completely in the complex plane. This approach goes well beyond the rainbow-ladder approximation and permits us to investigate the influence of the gluon self-interaction on the properties of mesons. As a first result we find indications of a nonperturbative cancellation of the gluon self-interaction contributions and pion cloud effects in the mass of the rho meson.

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Available from: Richard Williams, Sep 22, 2014
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    • "Prominent examples for hadron properties studied in such a setup in rainbow-ladder truncation (which is specified further below) include leptonic decay constants [46–48], hadronic decays [49,50], and electromagnetic properties of both mesons [51–55] and baryons [56–61]. Improvements to this truncation have been considered in the past and studies in this direction are under way [62–67]. What we discuss in the present work is most easily exemplified in a simple truncation, but becomes more important — and thus relevant — with any kind of increasing numerical effort necessitated by either a more involved truncation or the study of a system of more than two constituents. "
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