[Zhou, Li-Juan] Guangxi Univ Technol, Dept Informat & Comp Sci, Liuzhou 545006, Peoples R China
; [Zhou, Li-Juan] Hua Zhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China
; [Kisslinger, Leonard S.] Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA
; [Ma, Wei-xing] Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
The nonlocal vacuum condensates of QCD describe the distributions of quarks and gluons in the nonperturbative QCD vacuum. Physically, this means that vacuum quarks and gluons have nonzero mean squared momentum, called virtuality. In this paper we study the quark virtuality which is given by the ratio of the local quark-gluon mixed vacuum condensate to the quark local vacuum condensate. The two vacuum condensates are obtained by solving Dyson-Schwinger equations of a fully dressed quark propagator with an effective gluon propagator. Using our calculated condensates, we obtain the virtuality of quarks in the QCD vacuum state. Our numerical predictions are consistent with other theoretical model calculations such as QCD sum rules, lattice QCD and instanton models.