Summary
In this paper we propose a new use of the complex-angular-momentum representation of the scattering amplitude. In particular we show that it is not possible to connect a sequence of compound-state resonances with a pole trajectory. Furthermore the high-energy backward peaks in the elastic channel are analysed, and we propose a model of the mechanism responsible for these backward enhancements. The mathematical formalism of this model, which employs the poles of theS-matrix in the complex-angular-momentum plane, is investigated in detail. Finally, in order to test the theory, a phenomenological analysis is performed; the results that we obtain are in agreement with the theory.
Riassunto
In questo lavoro si propone un nuovo uso della rappresentazione dell’ampiezza di diffusione nel piano del momento angolare complesso. Si dimostra in primo luogo che una traiettoria non può interpolare più risonanze nucleari, dovute alla formazione di nuclei composti nel senso di Bohr. Si studiano poi i picchi a grandi angoli nel canale elastico ad alta energia, e si propone un modello del meccanismo responsabile di questi picchi all’indietro. Si analizza in dettaglio il formalismo matematico di questo modello che usa i poli della matriceS nel piano del momento angolare complesso. Infine si sviluppa un’analisi fenomenologica i cui risultati sono in accordo con la teoria.
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Di Salvo, E., Viano, G.A. Sommerfeld poles and backward peaks in elastic scattering. Nuov Cim A 42, 49–66 (1977). https://doi.org/10.1007/BF02730307
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DOI: https://doi.org/10.1007/BF02730307