Electroproduction and Photoabsorption in a Model of Higher Baryon Couplings
- 1 April 1973
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review D
- Vol. 7 (7), 2111-2125
- https://doi.org/10.1103/physrevd.7.2111
Abstract
We have studied the two related problems of inelastic scattering and the total photoabsorption cross section in a relativistic SU(6) × O(3) model of higher baryon couplings developed over the last few years. The hypothesis of duality is incorporated for both these photonic processes by summing over an infinite sequence of -channel resonances, the facility for which is provided in this model of couplings through a simple structure of the form factor for the supermultiplet transition () and a "Regge universality" condition on the "reduced" coupling constants. A slight variant of this form factor, which has been applied successfully to several two-body processes recently, is found to give rather good fits to the resonance-production region of inelastic scattering over a wide range of input data. The difference () of the total photoabsorption cross section on the proton and the neutron targets is also reproduced quite accurately over the whole range of available data. For these two processes, the higher-spin () states are found to produce dominant contributions over those of the lower-spin () states. A comparison of this pattern with a corresponding one operative for the evaluation of electromagnetic masses within this model prompts us to infer almost a "causal" relationship between the positive value of on the one hand and the traditional negative value of () on the other. However, an important shortcoming of this model is its inability to reproduce the scaling region of deep-inelastic scattering for very high incident electron energies ( GeV). This is presumably because of the absence in this model of a mechanism for the inclusion of daughter trajectories, whose contributions are expected to be progressively more important as the energy is increased.
Keywords
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