Backward Elastic p3He Scattering at Energies 1 - 2 GeV

The two-body transfer amplitude for the rearrangement process i+(jkl) - j+(ikl) is constructed on the basis of technique of 4-dimensional covariant nonrelativistic graphs. The developed formalism is applied to describing backward elastic $p^3He$ scattering in the energy range 0.5 - 1.7 GeV. Numerical calculations performed using the 5- channel wave function of the $^3He$ nucleus show that the transfer of a noninteracting np- pair dominates and explains satisfactorily the energy and angular dependence of the differential cross section at energies 0.9 - 1.7$GeV. A weak sensitivity to high momentum components of the$~^3He$ wave function in spite of large momentum transfer as well as a very important role of rescatterings in the initial and final states are established.