2020 Impact factor 3.043
Hadrons and Nuclei
Eur. Phys. J. A 15, 409-416 (2002)
DOI: 10.1140/epja/i2002-10036-6

Mesons of the $\mth{f_0}$ family in processes $\mth{\pi\pi\to\pi\pi,K\overline{K}}$ up to 2 GeV and the chiral-symmetry breaking

Yu.S. Surovtsev1, D. Krupa2 and M. Nagy2

1  Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna 141 980, Moscow Region, Russia
2  Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, 842 28 Bratislava, Slovakia

surovcev@thsun1.jinr.ru
krupa@savba.sk
fyzinami@nic.savba.sk

(Received: 25 April 2002 / Published online: 26 November 2002)

Abstract
In a combined analysis of the experimental data on the coupled processes $\pi\pi\to\pi\pi,K\overline{K}$ in the channel with IGJPC=0+0++, the various scenarios of these reactions (with different numbers of resonances) are considered. In a model-independent approach, based only on analyticity and unitarity, a resonance is represented by a pole cluster (poles on the Riemann surface) of the definite type that is defined by the state nature. The best scenario contains the resonances f0(665) (with properties of the $\sigma$-meson), f0(980) (with a dominant $s{\bar s}$ component), f0(1500) (with a dominant flavour-singlet, e.g., glueball component) and the f0(1710) (with a considerable $s{\bar s}$ component). If the f0(1370) exists, it has a dominant $s{\bar s}$ component. The coupling constants of the observed states with the considered channels and the $\pi\pi$ and $K\overline{K}$ scattering lengths are obtained. The conclusion on the linear realization of chiral symmetry is drawn.

PACS
11.55.Bq - Analytic properties of S-matrix.
11.80.Gw - Multichannel scattering.
12.39.Mk - Glueball and nonstandard multi-quark/gluon states.
14.40.Cs - Other mesons with S=C=0, mass < 2.5 GeV.

© Società Italiana di Fisica, Springer-Verlag 2002