Decay Modes of the Mesonη′(958)and Chiral-Symmetry Breaking

Using the simple model that the amplitude for ${\eta }^{\prime }\to \eta \pi \pi$ is dominated by the $\delta \mathrm{}\left(970\right)\mathrm{}$ resonance we find a satisfactory fit to the data. The quadratic mass formula for $\eta -{\eta }^{\prime }$ mixing with a positive mixing angle (i.e. reduction of $s\overline{s}$ content in the physical $\eta$ state) is preferred in agreement with the requirement for ${\eta }^{\prime }\to 2\gamma$. Failure of the current-algebra calculation for ${\eta }^{\prime }\to \eta \pi \pi$ is explained and is shown not to be evidence against the (3*, 3) ⊕ (3, 3*) model of chiral-symmetry breaking.