Elastic scattering of antiprotons from carbon, calcium, and lead at 180 MeV

Angular distributions for elastic scattering of 180 MeV antiprotons from 12C, 40Ca, and 208Pb have been measured over a wide angular range with a magnetic spectrometer. In general, microscopic calculations agree fairly well with the data. Optical-model fits with Woods-Saxon parametrization determine the magnitude and the relative strength of the real and imaginary potentials at the nuclear surface. When the shape of the potentials is derived from that of the charge distribution, the depth of the real potential is found to be shallow (30 MeV < V 0 < 70 MeV). These results are in some disagreement with several models and predictions, but are consistent with the results of p - 12 C scattering at 46.8 MeV and with a recent a analysis of p - atom data.