Quark flavor effects on gluon and ghost propagators

A. B. wishes to acknowledge the financial grants CONACyT Project No. 46614-F and Coordinacion de la Investigacion Cientifica (CIC) Project No. 4.10 and U.S. Department of Energy, Office of Nuclear Physics, Contract No. DE-AC02-06CH11357. The work of M. C. is supported by the AuroraScience project, which is funded jointly by the Provincia Autonoma di Trento (PAT) and the Istituto Nazionale di Fisica Nucleare (INFN). Part of the calculations were performed using the Aurora Supercomputer at the Fondazione Bruno Kessler (Trento). J.R.-Q. is indebted to O. Pene, Ph. Boucaud, B. Blossier, K. Petrov and C. D. Roberts for fruitful discussions and very helpful comments, and also acknowledges the Spanish MICINN for the support by the Research Project No. FPA2011-23781 and "Junta de Andalucia" by Project No. P07FQM02962.