Hadron Scattering Research Articles

Nonforward Scattering of Hadrons and High-Energy Phenomenology

This review is divided into three parts. First, we survey the general features of nonforward scattering. We comment on two large-angle scattering models (the statistical model and the proposal for explaining the "breaks" in the differential cross section in terms of production cross sections) and discuss the axiomatic results on lower bounds and the asymptotic angular dependence. Second, we review the motivation and the general formalism of the multiple-scattering model and the qualitative success of the model---in particular, its application to the nonforward scattering. Third, we discuss the impact of the multiple-scattering model on high-energy phenomenology. Here, we emphasize that, in addition to providing a concrete model for large $|t|$ scattering, the multiple-scattering model contains virtues from both the optical model and the Regge-pole model. Similar to the absorption model, it helps to explain problems encountered in a pure Regge-pole model. On the other hand, it preserves the past success of the Regge-pole model and opens new possibilities for it.

Elastic Diffraction Scattering of Hadrons at High Energies

A new model for the high-energy (${p}_{\mathrm{lab}}\ensuremath{\ge}4$ GeV/c) diffraction scattering of hadrons is presented. This shadow-scattering model explains, quantitatively, the magnitude and energy dependence of the widths of elastic-scattering diffraction peaks. An improved approximation for the inelastic intermediate states is used which emphasizes the role of quasielastic scattering and of optical absorption with energy-independent opacity. The quasielastic scattering is calculated from Feynman diagrams, while the optical absorption is constrained by the observed total cross section. Unitarity and one energy-independent scale-fixing parameter, then, give quantitative predictions for the widths of diffraction peaks which are only weakly dependent on the assumed $l$ dependence of the optical absorption.

A Phenomenological Representation of High Energy Scattering of Hadrons

Experimental data on two-body and quasi two-body collisions of the high energy hadrons are analyzed in terms of the phenomenological representations· for the partial wave transition amplitudes which are suggested from the K-matrix approach of the multi-channel problem and the dominance of the one-particle-exchange mechanism. It is shown that the angular distri­ bution and the real-imaginary ratio of the forward elastic amplitudes are well represented by appropriate choice of the parameters. The form of the quasi two-body inelastic transition amplitudes is also discussed in relation to the forward peaks of the differential cross sections and the real-imaginary ratios of the amplitudes.

THE NONRELATIVISTIC QUARK MODEL

CONTENTS Introduction I. The Nonrelativistic Quark Model and the Classification of Hadrons 109 II. Mass Formulas in the Quark Model 110 III. Electromagnetic Properties of Hadrons 112 IV. Weak Interactions of Hadrons 115 V. Scattering of High-energy Particles (Description of the Model) 116 VI. Main Consequences of the Quark Model for the Scattering of High-energy Hadrons 117 VII. Relations between Total Cross Sections 118 VIII. Relations between Differential Cross Sections for Inelastic Reactions 120 IX. The Density Matrix 122 X. Collisions of High-energy Hadrons (Relations between the Nonrelativistic Quark Model and other Theories) 123 XI. Conclusion 124 What Should be Measured and Why 124 Appendix I. Hadron Wave Functions in the Quark Model 125 Appendix II 126 Literature Cited 127