A practical guide to unravel time-like transition form factors

A method to determine masses, widths and coupling constants of vector mesons, like phi(1020), omega(782) and rho(0)(770) recurrences is defined. Starting from data on decay rates and cross-sections for the processes: phi -> M-I gamma, phi -> M(I)e(+)e(-) and e(+)e(-) -> M-I phi, where M-I is a pseudoscalar or scalar meson with isospin I = 0, 1, the time-like transition form factors, which describe the vertex phi gamma M-I, are parameterized using a vector-meson-propagators description in the low-energy region (< 3 4 GeV), the quark-counting rule prescription for the high-energy behavior, and the analyticity imposed by means of the dispersion relations.