2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/189301According to the QCD expectations the lightest glueball should be a scalar particle (J^{PC}=0^{++}). Different scenarios have been considered for a classification of these states but -- despite considerable progress in recent years -- the experimental basis for various parameters is still rather weak. We present a new analysis of the elastic and charge exchange pi pi scattering between 1000 and 1800 MeV. A unique solution is selected which shows clear evidence for f_0(1500) and a broad state (σor ``f_0(1000)''), but there is no evidence for f_0(1370) at a level of \gtrsim 10% branching ratio to pi pi. Arguments in favour of the broad state to be a glueball are summarized.talk presented at QCD06, Montpellier, France, July3-7, 2006High Energy Physics - PhenomenologyScalar mesons: in search of the lightest glueballtext