TY  - JOUR
AU  - Aguilar, A. C.
AU  - Cardona, J. C.
AU  - Ferreira, M. N.
AU  - Papavassiliou, J.
PY  - 2017
DA  - 2017//
TI  - Non-Abelian Ball-Chiu vertex for arbitrary Euclidean momenta
T2  - Phys. Rev. D
JO  - Physical Review D
SP  - 014029
EP  - 29pp
VL  - 96
IS  - 1
PB  - Amer Physical Soc
AB  - We determine the non-Abelian version of the four nontransverse form factors of the quark-gluon vertex, using exact expressions derived from the Slavnov-Taylor identity that this vertex satisfies. In addition to the quark and ghost propagators, a key ingredient of the present approach is the quark-ghost scattering kernel, which is computed within the one-loop dressed approximation. The vertex form factors obtained from this procedure are evaluated for arbitrary Euclidean momenta, and display features not captured by the well-known Ball-Chiu vertex, deduced from the Abelian (ghost-free) Ward identity. Particularly interesting in this analysis is the so-called soft-gluon limit, which, unlike other kinematic configurations considered, is especially sensitive to the approximations employed for the vertex entering in the quark-ghost scattering kernel, and may even be affected by a subtle numerical instability. As an elementary application of the results obtained, we evaluate and compare certain renormalization-point-independent combinations, which contribute to the interaction kernels appearing in the standard quark gap and Bethe-Salpeter equations. In doing so, even though all form factors of the quark-gluon vertex, and in particular the transverse ones which are unconstrained by our procedure, enter nontrivially in the aforementioned kernels, only the contribution of a single form factor, corresponding to the classical (tree-level) tensor, will be considered.
SN  - 2470-0010
UR  - http://arxiv.org/abs/1610.06158
UR  - https://doi.org/10.1103/PhysRevD.96.014029
DO  - 10.1103/PhysRevD.96.014029
LA  - English
N1  - WOS:000406540300002
ID  - Aguilar_etal2017
ER  -