PT Journal
AU Binosi, D
   Papavassiliou, J
TI Gauge invariant Ansatz for a special three-gluon vertex
SO Journal of High Energy Physics
JI J. High Energy Phys.
PY 2011
BP 121
EP 23pp
VL 03
IS 3
DI 10.1007/JHEP03(2011)121
LA English
DE Nonperturbative Effects; QCD
AB We construct a general Ansatz for the three-particle vertex describing the interaction of one background and two quantum gluons, by simultaneously solving the Ward and Slavnov-Taylor identities it satisfies. This vertex is known to be essential for the gauge-invariant truncation of the Schwinger-Dyson equations of QCD, based on the pinch technique and the background field method. A key step in this construction is the formal derivation of a set of crucial constraints (shown to be valid to all orders), relating the various form factors of the ghost Green's functions appearing in the aforementioned Slavnov-Taylor identity. When inserted into the Schwinger-Dyson equation for the gluon propagator, this vertex gives rise to a number of highly non-trivial cancellations, which are absolutely indispensable for the self-consistency of the entire approach.
ER