Summary
Some related questions in coupled reactions are studied. An extension of the Omnes’ function for multi-channel processes is obtained, which reduces to the Fredholm determinant of the integral equations for the nonrelativistic case. It is especially suited towards obtaining a Levinson theorem for coupled cases. Next, assuming that the input is symmetric, a proof is given to show that the scattering matrix, fromND −1 equations, is symmetric and independent of the subtraction points when n2 different subtractions are chosen for an n-channel problem. Lastly, an approximate first-order scattering matrix is obtained, which is symmetric as well as subtraction-point-independent.
Riassunto
Si studiano alcune questioni relative alle reazioni accoppiate. Si ottiene una estensione della funzione di Omnès per processi a molti canali, che si riduce, nel caso non relativistico al determinante di Fredholm delle equazioni integrali. Essa è specialmente adatta per ottenere un teorema di Levinson per i casi accoppiati. Poi, nell’ipotesi che l’entrata sia simmetrica, si da la dimostrazione che la matrice dello scattering, dalle equazioniND −1, è simmetrica ed indipendente dai pnnti di sottrazione se si scelgonon 2 diverse sottrazioni per un problema adn canali. Infine si ottiene una matrice di scattering di primo ordine approssimata, che è simmetrica ed anche indipendente dal punto di sottrazione.
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Work supported in part by the U. S. Atomic Energy Commission.
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Nath, P., Srivastava, Y.N. Some remarks concerning coupledND −1 equations. Nuovo Cim 38, 1192–1200 (1965). https://doi.org/10.1007/BF02750600
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DOI: https://doi.org/10.1007/BF02750600