High-statistics study of. pi. /sup +/p,. pi. /sup -/p, and pp elastic scattering at 200 GeV/c

We have measured ..pi../sup +/p, ..pi../sup -/p, and pp elastic scattering at an incident-beam momentum of 200 GeV/c in the region of -t, four-momentum transfer squared, from 0.021 to 0.665 (GeV/c)/sup 2/. The data allow an investigation of the t dependence of the logarithmic forward slope parameter bequivalent(d/dt)(ln dsigma/dt). In addition to standard parametrizations, we use functional forms suggested by the additive quark model to fit the measured dsigma/dt distributions. Within the context of this model we estimate the size of the clothed quark in the pion and proton. Limits on the elastic-scattering amplitude derived from unitarity bounds are checked, and no violations are observed.