Related papers: Pinch Technique: Theory and Applications
The question of the definition of effective charges for non-abelian gauge theories is discussed, focusing in particular on both the pinch technique and background field method approaches. It is argued that there does exist a unique…
We outline the pinch technique for constructing gauge invariant Green's functions in gauge theories and derive the Ward identities that must be satisfied by the gauge invariant three boson vertices of the standard model. They are…
In the context of the Standard Model we show how to apply the pinch technique to four-fermion amplitudes with non-conserved external charged currents,in order to construct to one-loop order gauge independent self-energies and vertices. We…
The pinch technique (PT) is applied to obtain the gauge-independent resummed gluon self-energy in a hot Yang-Mills gas. Calculation is performed at one- loop level in linear gauges which preserve rotational invariance and the res ummed…
Using as ingredients the non-perturbative solutions of various QCD Green's function obtained from Schwinger-Dyson equations (SDEs), we study two versions of the QCD effective charge. The first one obtained from the pinch technique gluon…
The application of the background-field method to the electroweak Standard Model and its virtues are reviewed. Special emphasis is directed to the Ward identities that follow from the gauge invariance of the background-field effective…
The generalization of the pinch technique to all orders in perturbation theory is presented. The effective Green's functions constructed with this procedure are singled out in a unique way through the full exploitation of the underlying…
The consistent description of unstable particles, renormalons, or other Schwinger--Dyson-type of solutions within the framework of perturbative gauge field theories necessitates the definition and resummation of off-shell Green's functions,…
We show that the background field method (BFM) is a simple way of deriving the same gauge-invariant results which are obtained by the pinch technique (PT). For illustration we construct gauge-invariant self-energy and three-point vertices…
We show that the gauge invariant treatment of the Schwinger-Dyson equations of QCD leads to an infrared finite gluon propagator, signaling the dynamical generation of an effective gluon mass, and a non-enhanced ghost propagator, in…
The effective gluon propagator constructed with the pinch technique is governed by a Schwinger-Dyson equation with special structure and gauge properties, that can be deduced from the correspondence with the background field method. Most…
Application of the background-field method to the electroweak Standard-Model yields a gauge-invariant effective action giving rise to simple Ward identities. We find that in the background-field `t Hooft-Feynman gauge the resulting vertex…
The consistent description of resonant transition amplitudes within the framework of perturbative field theories necessitates the definition and resummation of off-shell Green's functions, which must respect several crucial physical…
A gauge-independent approach to resonant transition amplitudes with nonconserved external currents is presented, which is implemented by the pinch technique. The analytic expressions derived with this method are $U(1)_{em}$ invariant,…
The $S$-matrix pinch technique is used to derive an effective gluon self-energy to one-loop order, when the theory is quantized in the Coulomb gauge (CG) and in the temporal axial gauge (TAG). When the pinch contributions are added, the…
The generalization of the two-loop Pinch Technique to the Electroweak Sector of the Standard Model is presented. We restrict ourselves to the case of conserved external currents, and provide a detailed analysis of both the charged and…
In the context of the Standard Model we extend the S--matrix pinch technique for non--conserved currents to the case of three boson vertices. We outline in detail how effective gauge invariant three boson vertices can be constructed, with…
Non-Abelian gauge theories with composite fields are examined in the background field method. Generating functionals of Green's functions for a Yang--Mills theory with composite and background fields are introduced, including the generating…
The gauge-invariant three-gluon vertex obtained from the pinch technique is characterized by thirteen nonzero form factors, which are given in complete generality for unbroken gauge theory at one loop. The results are given in $d$…
We review the Pinch Technique - Background Field Method (PT-BFM) framework for formulating and solving the Schwinger-Dyson equations of Yang-Mills theories. In particular, we show how within this framework it is possible to write a new set…