[seminar] R. Alkofer, QCD Green Functions and their Application ...

[Kresimir Kumericki]

Prirodoslovno-matematicki fakultet
FIZICKI ODSJEK 
Bijenicka c. 32, Zagreb, Hrvatska

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                     SEMINAR  TEORIJSKE  FIZIKE
(Zajednicki seminari Fizickog odsjeka PMF-a te Odjela za fiziku IRB-a)

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QCD Green Functions and their Application to Hadron Physics:
Gluon positivity violation, dynamical scalar quark confinement, and the
nucleons' quark core

Reinhard Alkofer

Institut fuer Physik, Karl-Franzens-Universitaet Graz


Datum: 17. prosinca 2008. (srijeda)
Vrijeme: 11:00 sati (TOCNO!).
Mjesto: PMF, Fizicki odsjek, Bijenicka c. 32, F-201


Sazetak:

In a functional approach to  QCD the infrared behaviour of Landau gauge
Green functions is investigated. Positivity violation for, and thus
confinement of, gluons is demonstrated, and the analytic structure of
the gluon propagator is studied.
Quark confinement is related to an infrared divergence of the quark-gluon
vertex. In the latter various components are non-vanishing due to the
dynamical breaking of chiral symmetry. As a result an infrared finite
running coupling in the Yang-Mills sector is derived whereas the running
coupling related to the quark-gluon vertex is infrared divergent and
therefore implies quark confinement.
These results will be  used to formulate a covariant Faddeev approach to
nucleons. The resulting amplitudes describe the quark core of the nucleon.
Besides the mass of this state also the electromagnetic form factors are
calculated. The results for charge radii and magnetic moments as a
function of the quark current mass provide some indication what
the missing pion cloud may contribute to the nucleons' properties.


2008-12-10 

Voditelj seminara:
dr. Kresimir Kumericki (kkumer at phy.hr)