Scalar mesons in η′ → ηπ 0 π 0 decay

η → π + π − π 0 γ in Chiral Perturbation Theory

Chiral Dynamics of scalar mesons : radiative φ decay and σ in the medium through π 0 π 0 nuclear photoproduction February 8 , 2008

Properties of the light scalar mesons face the experimental data on the φ → π 0 π 0 γ decay and the ππ scattering

Properties of the light scalar mesons face the experimental data on the φ → π 0 π 0 γ decay and the ππ scattering Abstract The high-statistical KLOE data on the φ → π 0 π 0 γ decay are described simultaneously with the data on ππ scattering and the ππ → K ¯ K reaction. The description is carried out taking into account the chiral shielding of the putative σ(600) meson and it's mixing with the w...

γγ → π 0 π 0 and η → π 0 γγ at O ( p 6 ) in the NJL model

We discuss the processes ! 0 0 and ! 0 at O(p 6) in the momentum expansion. The calculation involves tree{level, one{loop and two{loop diagrams of a chiral eeective lagrangian which is obtained by a bosonization of the NJL model. The importance of integrating out meson resonances (reduction) is pointed out. Our nal results for the total cross section of ! 0 0 are in good agreement with the expe...

Parameters and Application to Π 0 , Η , Η ′

The chiral expansion of the low energy processes π 0 → γγ and η → γγ is reconsidered with particular emphasis on the question of the evaluation of the two low-energy parameters from L W Z (6) which are involved at chiral order six. It is shown how extensive use of sum-rules and saturation with resonances as well as constraints from asymptotic QCD effectively determine their values. Predictions ...