η′→ηππ decay as a probe of a possible lowest-lying scalar nonet

We study the ${\eta }^{\prime }\to \eta \pi \pi$ decay within an effective chiral Lagrangian approach in which the lowest lying scalar meson candidates $\sigma \mathrm{}\left(560\right)\mathrm{}$ and $\kappa \mathrm{}\left(900\right)\mathrm{}$ together with the $f_0\mathrm{}\left(980\right)\mathrm{}$ and $a_0\mathrm{}\left(980\right)\mathrm{}$ are combined into a possible nonet. We show that there exists a unique choice of the free parameters of this model which, in addition to fitting the $\pi \pi$ and $\pi K$ scattering amplitudes, well describes the experimental measurements for the partial decay width of ${\eta }^{\prime }\to \eta \pi \pi$ and the energy dependence of this decay. As a by-product, we estimate the $a_0\mathrm{}\left(980\right)\mathrm{}$ width to be 70 MeV, in agreement with a new experimental analysis.