  In this paper we show how the differential cross-section of elastic proton
scattering can be calculated from the square of the transmitted four-momentum
using the model of multiparticle fields. We consider a single-loop diagram and
the corresponding analytical expression for this loop. This expression contains
a multidimensional integral over virtual four-momentum, which we calculate
using the Laplace method. These multidimensional integrals were reduced to
two-dimensional or one-dimensional and then were calculated numerically. A
qualitative correspondence of the differential cross section to the
experimental data is obtained. Achieving a quantitative match with the
experiment requires taking into account more loop diagrams.
