The infrared properties of the transverse structure of the quark-gluon vertex
Light-quark meson description with Schwinger-Dyson equations of quantum chromodyna...
Connections between string theory and gauge theory via scattering amplitudes
| Full text | |
| Author(s): |
Aguilar, A. C.
;
Ferreira, M. N.
;
Figueiredo, C. T.
;
Papavassiliou, J.
Total Authors: 4
|
| Document type: | Journal article |
| Source: | PHYSICAL REVIEW D; v. 99, n. 9, p. 30-pg., 2019-05-10. |
| Abstract | |
We present the detailed derivation of the longitudinal part of the three-gluon vertex from the Slavnov-Taylor identities that it satisfies, by means of a nonperturbative implementation of the Ball-Chiu construction; the latter, in its original form, involves the inverse gluon propagator, the ghost dressing function, and certain form factors of the ghost-gluon kernel. The main conceptual subtlety that renders this endeavor nontrivial is the infrared finiteness of the gluon propagator, and the resulting need to separate the vertex into two pieces, one that is intimately connected with the emergence of a gluonic mass scale, and one that satisfies the original set of Slavnov-Taylor identities, but with the inverse gluon propagator replaced by its "kinetic" term. The longitudinal form factors obtained by this construction are presented for arbitrary Euclidean momenta, as well as special kinematic configurations, parametrized by a single momentum. A particularly preeminent feature of the components comprising the tree-level vertex is their considerable suppression for momenta below 1 GeV, and the appearance of the characteristic "zero-crossing" in the vicinity of 100-200 MeV. Special combinations of the form factors derived with this method are compared with the results of recent large-volume lattice simulations, and are found to capture faithfully the rather complicated curves formed by the data. A similar comparison with results obtained from Schwinger-Dyson equations reveals a fair overall agreement, but with appreciable differences at intermediate energies. A variety of issues related to the distribution of the pole terms responsible for the gluon mass generation are discussed in detail, and their impact on the structure of the transverse parts is elucidated. In addition, a brief account of several theoretical and phenomenological possibilities involving these newly acquired results is presented. (AU) | |
| FAPESP's process: | 17/05685-2 - Hadronic physics in high energy nuclear collisions |
| Grantee: | Jun Takahashi |
| Support Opportunities: | Special Projects |
| FAPESP's process: | 17/07595-0 - Nonperturbative aspects of the QCD Green's functions |
| Grantee: | Arlene Cristina Aguilar |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 16/11894-0 - Aspects of the dynamical mass generation in the formalism of the Schwinger-Dyson equations |
| Grantee: | Clara Teixeira Figueiredo |
| Support Opportunities: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 18/09684-3 - The infrared properties of the transverse structure of the quark-gluon vertex |
| Grantee: | Clara Teixeira Figueiredo |
| Support Opportunities: | Scholarships abroad - Research Internship - Doctorate |