A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2017; you can also visit the original URL.
The file type is
Physical Review D
We discuss the two photon coupling of the lightest scalar meson on the basis of an extension of χPT. Using low energy data on the pion form-factor and the γγ→π^+π^-(π^0π^0) cross-sections as inputs, we find Γ(σ→γγ) 0.126 keV . The smallness of the result and the relative weight between its components, Γ_γγ→ S_1Γγγ→ππ→ S_1 < 1, suggests that the scalar 0^++ meson is mainly a Q^2Q̅^2 state.doi:10.1103/physrevd.92.074008 fatcat:yiqv5tq6c5borg56hk2hgl7rem