Summary
Elastic scattering experiments from 300 to 1300 MeV are analysed by various new or improved techniques. The usual D13 andF 15 assignments for the second and third resonances are supported. The fourth resonance is found to be F37, and the 800 MeV π+p shoulder to be D35 inelastic. There are also indications of four more inelastic shoulders: in P11∼400 MeV), S11∼ 600 MeV), D15∼ 700 MeV) and G17∼ 1200 MeV). BothS waves increase steadily with energy, indicating a strong repulsive core. The background at the fourth resonance is strongly spindependent, in contradiction to the usual diffraction model. The imaginary parts of the partial amplitudes are obtained quantitatively over much of this region. The most powerful new condition is the requirement that the elasticities of the resonances, as determined from total cross-sections and forward dispersion relations, be compatible with the differential cross-sections there.
Riassunto
Con varie tecniche nuove o migliorate si analizzano gli esperimenti di scattering elastico fra 300 e {dy1300} MeV. Si convalidano le usuali assegnazioni D13 e F15 alla seconda e terza risonanza. Si trova che la quarta risonanza è F37, e che il ginocchio π+p di 800 MeV è D35 anelastico. Si hanno anche indicazioni di altri quattro ginocchi anelastici: in P11u∼ 400 MeV), Su∼600 MeV), D15∼ 700 MeV) e G17∼ {dy1200} MeV). Entrambe le ondeS crescono fortemente con l’energia, indicando un core fortemente ripulsivo. Il fondo della quarta risonanza dipende fortemente dallo spin, in contraddizione coll’usuale modello di diffrazione. Si ottengono quantitativamente le parti immaginarie delle ampiezze parziali entro la maggior parte di questa regione. La più potente condizione nuova è l’esigenza che le elasticità delle risonanze, determinate dalle sezioni d’urto totali e dalle relazioni di dispersione in avanti, siano compatibili ivi con le sezioni d’urto differenziali.
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The research reported in this document has been sponsored in part by the Air Force Office of Scientific Research OAR through the European Office Aerospace Research United States Air Force.
National Science Foundation post-doctoral fellow.
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Auvil, P., Lovelace, C. πp phenomenology, (300÷1300) MeV. Nuovo Cim 33, 473–519 (1964). https://doi.org/10.1007/BF02750207
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DOI: https://doi.org/10.1007/BF02750207