Guangxi Univ Technol, Dept Informat & Comp Sci, Liuzhou 545006, Peoples R China
; Guangxi Univ, Dept Phys, Nanning 530004, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
Based on the Dyson-Schwinger equations (DSEs) in the 'rainbow' approximation, we investigate the quark virtuality in the vacuum state and quantum-chromodynamics (QCD) vacuum condensates. In particular, we calculate the local quark vacuum condensate and quark-gluon mixed condensates, and then the virtuality of quark. The calculated quark virtualities are lambda(u,d)(2) = 0.7 GeV2 for u, d quarks, and lambda(s)(2) = 1.6 GeV2 for s quark. Our theoretical predictions are consistent with empirical values used in QCD sum rules, and also fit to lattice QCD predictions.