Abstract
The present status of elastic and scattering in the high-energy domain is reviewed, with emphasis on the forward and near-forward regions. The experimental techniques for measuring , , and are discussed, emphasizing the importance of the region in which the nuclear and Coulomb scattering interfere. The impact-parameter representation is exploited to give simple didactic demonstrations of important rigorous theorems based on analyticity, and to illuminate the significance of the slope parameter and the curvature parameter . Models of elastic scattering are discussed, and a criterion for the onset of "asymptopia" is given. A critique of dispersion relations is presented. Simple analytic functions are used to fit simultaneously the real and imaginary parts of forward scattering amplitudes for both and , obtained from experimental data for and . It is found that a good fit can be obtained using only five parameters (with a cross section rising as ), over the energy range GeV. The possibilities that (a) the cross section rises only as , (b) the cross section rises only locally as , and eventually goes to a constant value, and (c) the cross-section difference between and does not vanish as are examined critically. The nuclear slope parameters are also fitted in a model-independent fashion. Examination of the fits reveals a new regularity of the and the systems. Predictions of all of the elastic scattering parameters are made at ultrahigh energies, and are compared to the available SPS collider measurements.
DOI:https://doi.org/10.1103/RevModPhys.57.563
©1985 American Physical Society