Analytic parametrizations of the non-perturbative Pomeron and QCD-inspired models

We consider several classes of analytic parametrizations of hadronic scattering amplitudes, and compare their predictions to all available forward data (pp, ¯ pp,�p,Kp, p, ,�p). Although these parametrizations are very close for √ s ≥ 9 GeV, it turns out that they differ markedly at low energy, where a universal Pomeron term ∼ ln 2 s enables one to extend the fit down to √ s = 4 GeV.