Guangxi Univ Technol, Dept Informat & Comp Sci, Liuzhou 545006, Peoples R China
; CAS, Inst High Energy Phys, Beijing 100049, Peoples R China
Based on Dyson-Schwinger Equations of quark propagator, we calculate quark-gluon mixed vacuum condensates (0 1 : (q) over barg(n)sigma(mu v)G(mu v)q:10) and quark vacuum condensates (01 : (q) over barq: 10) which are not only related to virtuality of quark in vacuum state but also characterize the space width of quark distribution in the vacuum. The existence of these vacuum condensates reflects in a direct way the non-perturbative structure of QCD vacuum. Our calculated results on the mixed condensates lead to quark virtualities of lambda(u,d)(2) = 0.7 GeV2 for u, d quarks, and lambda(s)(2). = 1.6 GeV2 for a quark which are consistent with other's calculations using completely different methods.