Measurement of π0 meson photoproduction cross section on 4He at the Esub(γ)=1.5-4.5 GeV in the region of small momentum transfers

Differential cross sections of π0-meson elastic photoproduction on helium nuclei at 1.5-4.5 GeV photon energy in the range of angles THETAsub(π)=2-8 deg are measured in the bremsstrahlung beam of the synchrotron. Parameters of ω-meson trajectory are obtained. The determined values of the reaction differantial cross sections and their statistical errors at Esub(γ) energies of incidence photons in the ranges 1.5-2.5; 2.5-3.5; 3.5-4.5 GeV after the comparison of the results of two measurement series are presented in the graphical and table form. The results agree with theoretical data of other papers with account of systematic errors which might attain 25%. Possible contributions of inelastic interactions and elastic photoproduction of ω-, eta, rho-mesons were simulated by the Monte-Carlo method. The combined contribution of background reactions of the measured cross section of the reaction turned to be < 1%