A practical guide to unravel time-like transition form factors

摘要

A method to determine masses, widths and coupling constants of vector mesons, like φ(1020), ω(782) and ρ0(770) recurrences is defined. Starting from data on decay rates and cross-sections for the processes: φ → MIγ, φ → MIe+e- and e+e- → MIφ, where MI is a pseudoscalar or scalar meson with isospin I = 0, 1, the time-like transition form factors, which describe the vertex φγMI , 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.