2019-04-21T08:24:00Z
http://digital.csic.es/dspace-oai/request
oai:digital.csic.es:10261/28158
2016-03-09T12:35:47Z
com_10261_61
com_10261_4
col_10261_314
Papavassiliou, Joannis
Aguilar, Arlene Cristina
Binosi, D.
2010-07-01
Journal of High Energy Physics 7: 002 (2010)
1126-6708
10261/28158
10.1007/JHEP07(2010)002
We use recent lattice data on the gluon and ghost propagators, as well as the Kugo-Ojima function, in order to extract the non-perturbative behavior of two particular definitions of the QCD effective charge, one based on the pinch technique construction, and one obtained from the standard ghost-gluon vertex. The construction relies crucially on the definition of two dimensionful quantities, which are invariant under the renormalization group, and are built out of very particular combinations of the aforementioned Green's functions. The main non-perturbative feature of both effective charges, encoded in the infrared finiteness of the gluon propagator and ghost dressing function used in their definition, is the freezing at a common finite (non-vanishing) value, in agreement with a plethora of theoretical and phenomenological expectations. We discuss the sizable discrepancy between the freezing values obtained from the present lattice analysis and the corresponding estimates derived from several phenomenological studies, and attribute its origin to the difference in the gauges employed. A particular toy calculation suggests that the modifications induced to the non-perturbative gluon propagator by the gauge choice may indeed account for the observed deviation of the freezing values.
eng
openAccess
Nonperturbative Effects
QCD
QCD effective charges from lattice data
ArtÃculo