RT Journal Article T1 What the infrared behavior of QCD vertex functions in Landau gauge can tell us about confinement A1 Llanes Estrada, Felipe José A1 Alkofer, R. A1 Fischer, C. S. A1 Schwenzer, K. AB The infrared behavior of Landau gauge QCD vertex functions is investigated employing a skeleton expansion of the Dyson Schwinger and Renormalization Group equations. Results for the ghost-gluon, three-gluon, four-gluon and quark-gluon vertex functions are presented. Positivity violation of the gluon propagator, and thus gluon confinement, is demonstrated. Results of the Dyson-Schwinger equations for a finite volume are compared to corresponding lattice data. It is analytically demonstrated that a linear rising potential between heavy quarks can be generated by infrared singularities in the dressed quark-gluon vertex. The selfconsistent mechanism that generates these singularities necessarily entails the scalar Dirac amplitudes of the full vertex and the quark propagator. These can only be present when chiral symmetry is broken, either explicitly or dynamically. PB World Scientific Publ Co Pte Ltd SN 0218-3013 YR 2007 FD 2007-10 LK https://hdl.handle.net/20.500.14352/50796 UL https://hdl.handle.net/20.500.14352/50796 LA eng NO © World Scientific Publishing CompanyR. Alkofer Alkofer thanks the organizers of X Hadron Physics 2007 for inviting him to give a seminar at this extraordinarily interesting workshop. This work has been supported in part by the DFG under contract AL 279/5-1 and by the FWF under contract M979-N16.Hadron Physics Workshop (10. 2007. Florianopolis, Brasil) NO DFG NO FWF DS Docta Complutense RD 19 abr 2025