Properties of scalar--isoscalar mesons from multichannel interaction analysis below 1800 MeV

TL;DR

This paper analyzes scalar-isoscalar mesons below 1800 MeV using a multichannel unitary model, revealing the properties of several resonances and comparing their branching ratios with experimental data.

Contribution

It introduces a multichannel interaction model for scalar-isoscalar mesons and identifies multiple resonances consistent with experimental observations.

Findings

Identification of a wide f0(500) resonance.

Observation of a narrow f0(980) resonance.

Detection of two resonances around 1300-1500 MeV similar to f0(1370) and f0(1500).

Abstract

Scalar-isoscalar mesons are studied using an unitary model in three channels: pi-pi, K-anti K and an effective 2pi-2pi. All the solutions, fitted to the pi-pi and K-anti K data, exhibit a wide f0(500), a narrow f0(980) and two relatively narrow resonances, lying on different sheets between 1300 MeV and 1500 MeV. These latter states are similar to the f0(1370) and f0(1500) seen in experiments at CERN. Branching ratios are compared with available data. We have started investigations of some crossing symmetry and chiral constraints imposed near the pi-pi threshold on the scalar-isoscalar, scalar-isotensor and P-wave pi-pi amplitudes.