Elastic pd and p4He scattering at intermediate energies

The differential cross sections for elastic p4He and pd small angle scattering were measured at energies 991, 890, 793 and 695 MeV, using incident proton beams of the LNPI synchrocyclotron. The systematic error in absolute normalization of the cross section is ±2%. Both the recoil particles and the forward protons were detected in this experiment. The total cross section and diffraction-cone slope parameter for p4He scattering have been extracted from the experimental data. The results of the measurements are compared to a calculation based on diffraction multiple-scattering theory in which nucleon-nucleon amplitudes obtained from a phase-shift analysis were used. It is shown that the slope of the calculated differential cross sections systematically exceeds the slope of the experimental cross sections p4He scattering, unlike pd scattering. It is noted that one of the possible reasons for the observed discrepancy can be an admixture of multiquark bag in the4He nucleus. (orig.)