eta' to eta pi pi Decay as a Probe of a Possible Lowest-Lying Scalar Nonet

TL;DR

This paper investigates the eta' to eta pi pi decay using an effective chiral Lagrangian with scalar mesons, providing insights into scalar nonet structure and decay mechanisms.

Contribution

It introduces a model that fits scattering data and decay measurements, offering a consistent description of scalar mesons and eta' decay processes.

Findings

The model accurately reproduces eta' to eta pi pi decay width.

Estimated a0(980) width is 70 MeV, aligning with recent experiments.

Provides a unified description of scalar meson nonet in decay analysis.

Abstract

We study the eta' to eta pi pi decay within an effective chiral Lagrangian approach in which the lowest lying scalar meson candidates sigma(560) and kappa(900) together with the f0(980) and a0(980) 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' to eta pi pi and the energy dependence of this decay. As a by-product, we estimate the a0(980) width to be 70 MeV, in agreement with a new experimental analysis.