  Based on the mathematically well defined Pad\'e Theory, a theoretically safe
new procedure for the extraction of the pole mass and width of resonances is
proposed. In particular, thanks to the Montessus de Ballore's theorem we are
able to unfold the Second Riemann sheet of an amplitude to search the position
of the resonant pole in the complex plane. The method is systematic and
provides a model-independent treatment of the prediction and the corresponding
errors of the approximation. This letter partially covers the material
presented by the author at the 15th International QCD Conference: QCD 10 (25th
anniversary), Montpellier, France, 28 Jun - 3 Jul 2010 and at the Quark
Confinement and the Hadron Spectrum IX, 30 August - 3 September 2010, Madrid,
Spain.
