An analysis of f_0-sigma mixing in light cone QCD sum rules
  We investigate f_0-sigma mixing in the framework of light cone QCD sum rules and by employing the experimental results about the decay widths and the masses of these scalar mesons we estimate the scalar mixing angle by using sigma meson data and f_0 meson data. The two values we thus obtain of the scalar mixing angle are not entirely consistent with each other, possibly indicating that the structure of these mesons cannot be simple quark-antiquark states. 
A. Gokalp, Y. Sarac and O. Yilmaz (Physics Department, Middle East   Technical University, Ankara, Turkey)