Mixing effect on the scalar glueball mass in QCD sum rules

We consider the mass dependence on the mixing between a pure glueball and a normal <q(q)over bar> meson in QCD sum rules. In the normal correlation functions, the gluonic current and <q(q)over bar> current are assumed to couple to both glueball and <q(q)over bar> states. By using the low-energy theorem, we construct a sum rule for the mixing correlation function (the gluonic current and the <q(q)over bar> current). Through these relationships and based on the assumption of two states (one glueball and one <q(q)over bar> meson) dominance, we find the masses of the 0(++) lowest-lying glueball and <q(q)over bar> meson.