Proton-deuteron elastic scattering at small momentum transfer from 50 to 400 GeV/c

Proton-deuteron elastic scattering has been measured in the four-momentum transfer squared region $0.013<|t|<0.14$ (GeV/c)² and for incident proton beam momenta from 50 to 400 GeV/c. The data can be fitted with the Bethe interference formula. We observe shrinkage of the diffraction cone with increasing energy equal to (0.94±0.04)ln(s/1 GeV²) (GeV/c)^-2. This shrinkage is greater than that observed in pp elastic scattering. The ratio of the elastic to the total cross section is approximately 0.1 and independent of energy above {~} 150 GeV. In order to extract information on $pn$ scattering we fit our data using the Glauber approach and a form factor which is the sum of exponentials. The values we obtain for the slope parameter in $pn$ scattering are sensitive to the details of the inelastic double-scattering term.