Analytic parametrization of high energy forward scattering amplitude II. K±p and π±p scattering

The K^±p and π^±p forward scattering amplitudes are parametrized in terms of functions which are analytic in the cut E plane and which give the asymptotic behaviour of the total cross sections of the type c (log E/E_o)^γ, E being the lab energy. Fits to high-energy data give, in particular, the best value of γ: around it we find, however, a large interval of positive values of γ which are also admissible on the basis of the χ² estimation.Being equally good from the point of view of the existing experimental data, the different asymptotic growth rates γ do lead to different predictions, e.g., of the real part at high energies. A remarkable common feature is, however, a zero in the real part of the π⁺p and π^?p scattering amplitudes, which is predicted by all of our parametrizations to be between 52 and 80 GeV/c of the lab momentum.