Proton-helium elastic scattering from 40 to 400 GeV

The elastic proton-helium differential cross sections were determined for 5 different incident laboratory energies from 40 to 400 GeV in the range 0.003 < t absolute value < 0.52 (GeV/c)2. The differential cross section drops 4 to 5 orders of magnitude to the first dip at t absolute value = 0.22 (GeV/c)2. A Glauber analysis is performed on the data. The inelastic intermediate states are found to be important. The shrinkage of the slope of the differential cross section is measured. The rate of shrinkage is twice as large as in the p-p case. Results on the real part of the elastic scattering amplitude at forward angly and at the dip structure (t absolute value approx. = 0.22) are presented. 20 references