6533b823fe1ef96bd127eb97

RESEARCH PRODUCT

Isospin breaking andf0(980)-a0(980) mixing in theη(1405) →π0f0(980) reaction

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We make a theoretical study of the η (1405) → π 0 f 0 (980) and η (1405) → π 0 a 0 (980) reactions to determine the isospin violation and the mixing of the f 0 (980) and a 0 (980) resonances. We make use of the chiral unitary approach where these two resonances appear as dynamically generated by the meson-meson interaction provided by chiral Lagrangians. We obtain a very narrow shape for the f 0 (980) production in agreement with a BES experiment. As to the amount of isospin violation, assuming constant vertices for the primary η (1405) → π 0 K K and η (1405) → π 0 π 0 η production, we find results which are much smaller than found in the experimental BES paper. The problem is solved by using the primary production driven by η' → K *K followed by K ∗ → K π . Thus, we can predict absolute values for the ratio Γ(π 0 ,π + π − )/Γ(π 0 ,π 0 η ) which are in fair agreement with experiment.