The quark-gluon vertex and the QCD infrared dynamics

Autor(es)

Oliveira, Orlando ^{[1, 2]} ; de Paula, Wayne ^[2] ; Frederico, Tobias ^[2] ; de Melo, J. P. B. C. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Coimbra, Dept Fis, CFisUC, P-3004516 Coimbra - Portugal

^[2] Inst Tecnolog Aeronaut, Ctr Tecn Aeroespacial, Dep Fis, BR-12228900 Sao Jose Dos Campos, SP - Brazil

^[3] Univ Cruzeiro Sul, Lab Fis Teor & Computac, BR-01506000 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: EUROPEAN PHYSICAL JOURNAL C; v. 79, n. 2 FEB 6 2019.
• Citações Web of Science: 2

Resumo

The Dyson-Schwinger quark equation is solved for the quark-gluon vertex using the most recent lattice data available in the Landau gauge for the quark, gluon and ghost propagators, the full set of longitudinal tensor structures in the Ball-Chiu vertex, taking into account a recently derived normalisation for a quark-ghost kernel form factors and the gluon contribution for the tree level quark-gluon vertex identified on a recent study of the lattice soft gluon limit. A solution for the inverse problem is computed after the Tikhonov linear regularisation of the integral equation, that implies solving a modified Dyson-Schwinger equation. We get longitudinal form factors that are strongly enhanced at the infrared region, deviate significantly from the tree level results for quark and gluon momentum below 2 GeV and at higher momentum approach their perturbative values. The computed quark-gluon vertex favours kinematical configurations where the quark momentum p and the gluon momentum q are small and parallel. Further, the quark-gluon vertex is dominated by the form factors associated to the tree level vertex.mu and to the operator 2 p mu + q mu. The higher rank tensor structures provide small contributions to the vertex. (AU)

• Processo FAPESP: 17/01142-4 - Da descrição do regime não perturbativo da cromodinâmica quântica à aplicação da teoria quântica de campos à física da matéria condensada
• Beneficiário: Tobias Frederico
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisador Visitante - Internacional
• Processo FAPESP: 17/05660-0 - Estudos teóricos da estrutura e reações de núcleos exóticos e sistemas de muitos corpos
• Beneficiário: Brett Vern Carlson
• Modalidade de apoio: Auxílio à Pesquisa - Temático