On the mass, width and coupling constants of the f(0)(980)

(eng) Using the pole approach we determine the mass and width of the f_0(980); in particular, we analyze the possibility that two nearby poles are associated to it. We restrict our analysis to a neighborhood of the resonance, using \pi\pi data for the phase shift and inelasticity, and the invariant mass spectrum of the J/\psi\to\phi\pi\pi, \phi K\bar K decays. The formalism we use is based on unitarity and a generalized version of the Breit-Wigner parameterization. We find that a single pole describes the f_0(980), the precise position depending upon the \pi\pi data used. As a byproduct, values for the g_{f_0\pi\pi} and g_{f_0K\bar K} coupling constants are obtained. Comment: 18 pages, 2 figures. A new analysis including the latest pi-pi phase shift data is performed. To be published in Eur. Phys. J. C