Tensor Analyzing Power inpdBackward Scattering at GeV Energies

Measurements are reported of the spherical tensor component $t_{20}$ for 1.0-, 0.8-, and 0.4-GeV equivalent proton bombarding energies for elastic $p-d$ scattering between 155°-175°. They are very close to zero in disagreement with the predictions of nucleon exchange models, including the Kerman-Kisslinger model with $N^{*}$ components in the deuteron wave function. The experiment was performed with a vector- and tensor-polarized deuteron beam scattered from a liquid hydrogen target.