PT Journal
AU Aguilar, AC
   De Soto, F
   Ferreira, MN
   Papavassiliou, J
   Pinto-Gomez, F
   Rodríguez-Quintero, J
   Santos, LR
TI Nonperturbative four-gluon vertex in soft kinematics
SO Physics Letters B
JI Phys. Lett. B
PY 2024
BP 139065
EP 7pp
VL 858
DI 10.1016/j.physletb.2024.139065
LA English
DE Quantum chromodynamics; Four-gluon vertex; Lattice QCD; Schwinger-Dyson equations
AB We present a nonperturbative study of the form factor associated with the projection of the full four-gluon vertex on its classical tensor, for a set of kinematics with one vanishing and three arbitrary external momenta. The treatment is based on the Schwinger-Dyson equation governing this vertex, and a large-volume lattice simulation, involving ten thousand gauge field configurations. The key hypothesis employed in both approaches is the "planar degeneracy", which classifies diverse configurations by means of a single variable, thus enabling their meaningful "averaging". The results of both approaches show notable agreement, revealing a considerable suppression of the averaged form factor in the infrared. The deviations from the exact planar degeneracy are discussed in detail, and a supplementary variable is used to achieve a more accurate description. The effective charge defined through this special form factor is computed within both approaches, and the results obtained are in excellent agreement.
ER