2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/203370We investigate the determination of the pole associated to $σ$ from $ππ$ scattering data below the $K\bar{K}$ threshold, including the new precise data from $K_{e4}$ decay reported recently by the NA48/2 Collaboration. Using a large class of analytic parametrizations based on expansions in powers of conformal variables, we obtain for the mass and width of $σ$ values which are consistent with those calculated recently using ChPT and Roy equations, but have larger theoretical uncertainties.6 pages, talk at SCADRON 70 (Workshop on Scalar Mesons and Related Topics, Lisbon, 11-16 February 2008)High Energy Physics - Phenomenologytext