Mass and decay constant of I=1/2 scalar meson in QCD sum rule

We calculate the mass and decay constant of I=12 scalar mesons composed of quark-antiquark pairs based on QCD sum rule. The quark-antiquark pairs can be sq¯ or qs¯ (q=u,d) in quark model, the quantum numbers of spin and orbital angular momentum are S=1, L=1. We obtain the mass of the ground sate in this channel is 1.410±0.049GeV. This result favors that K0*(1430) is the lowest scalar state of sq¯ or qs¯. We also predict the first excited scalar resonance of sq¯ is larger than 2.0 GeV.